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Mutual Redistribution BGP/OSPF with Dual-Homed eBGP Networks - Problems

spscisco
Level 1
Level 1

Hello,

 

Was really appreciate if someone can provide some assistances. We have a number of sites setup like the attached picture, all connect to AS65002 who is our MPLS provider.  

 

Each site has an internet connections and a connection to our MPLS provider, over the internet we have a tunnel where we peer with eBGP to the other sites, we also peer with our MPLS provider via eBGP. Within each site we have iBGP relationship between the routers who peer with eBGP and all devices have IGP (OSPF) between them.

 

We have noticed strange behaviour (routes-flapping and routing loops between iBGP neighbours) across the network. We have networks behind Routers C on both sites which are passed into OSPF and networks from Site A which are reached via Static.

 

The network was setup where in Site A, the static route from Router A was redistributed into BGP and OSPF and Router B had redistribution from OSPF to BGP and vice versa . For Site B, both Router A and B had redistribution from OSPF to BGP and vice versa.

 

Routes which are redistributed from BGP into OSPF have a metric set of 1000 and type E1 on Router A at both sites, compared to Router B where they are set to a metric to 1 and type E1.

 

We want to make sure the path via AS65002 is always preferred as it’s a much faster connections, if the 100Mbps link fails the network would transverse over the internet, using the eBGP tunnel.

 

I have read previously that you should not redistribute your BGP table into IGP. If I follow the advise and when the 100Mbps link fails, as I’ve not redistributed BGP into OSPF on Router A on both sites, Router C does not know about the networks which lives on the other site and therefore drops the connections – is this correct?

 

Which routers should be redistributing to what routing protocol?

 

I guess we also need to filter routes from the iBGP and eBGP neighbours to avoid loops? One of the think we have seen is a route shows up from BGP and then OSPF and then vice versa, causing a bouncing loop.

 

 

Thanks in advance.

17 Replies 17

rishrapsody1
Level 1
Level 1
Can you please share config of routerA and routerB?
Can you also check if your BGP session if flapping as well? or is it just the routes?

Hello, 

 

post the full configs of all 6 routers so we can lab this...

Hello,

 

I have attached a updated diagram with the IP addresses. 

 

All BGP and OSPF neighbours are stable.

 

When the link between AS65002 and Router B in Site B is disabled to test the backup (tunnel) route, I see the loop in Router A for 10.13.126.0/24, where it points to Router A in Site B and then back to Router B in Site A, see below:

 

RouterA#show ip route | i 10.13.126
B 10.13.126.1/32 [20/10] via 192.168.254.1, 00:00:01
RouterA#show ip route | i 10.13.126
B 10.13.126.1/32 [20/10] via 192.168.254.1, 00:00:03
RouterA#show ip route | i 10.13.126
B 10.13.126.1/32 [20/10] via 192.168.254.1, 00:00:04
RouterA#show ip route | i 10.13.126
B 10.13.126.1/32 [20/10] via 192.168.254.1, 00:00:04
RouterA#show ip route | i 10.13.126
B 10.13.126.1/32 [20/10] via 192.168.254.1, 00:00:05
RouterA#show ip route | i 10.13.126
B 10.13.126.1/32 [200/10] via 10.12.100.249, 00:00:01
RouterA#show ip route | i 10.13.126
B 10.13.126.1/32 [200/10] via 10.12.100.249, 00:00:02
RouterA#show ip route | i 10.13.126
B 10.13.126.1/32 [200/10] via 10.12.100.249, 00:00:02
RouterA#show ip route | i 10.13.126
B 10.13.126.1/32 [200/10] via 10.12.100.249, 00:00:03
RouterA#show ip route | i 10.13.126
B 10.13.126.1/32 [200/10] via 10.12.100.249, 00:00:04
RouterA#show ip route | i 10.13.126
B 10.13.126.1/32 [200/10] via 10.12.100.249, 00:00:04
RouterA#show ip route | i 10.13.126
B 10.13.126.1/32 [200/10] via 10.12.100.249, 00:00:05
RouterA#show ip route | i 10.13.126
B 10.13.126.1/32 [20/10] via 192.168.254.1, 00:00:01
RouterA#

 

 

RouterA#show ip bgp 10.13.126.1
BGP routing table entry for 10.13.126.1/32, version 784
Paths: (1 available, best #1, table default)
Flag: 0x820
Advertised to update-groups: (Pending Update Generation)
2
Refresh Epoch 1
65222 65222 65222 65222
192.168.254.1 from 192.168.254.1 (192.168.254.1)
Origin incomplete, metric 10, localpref 100, valid, external, best


RouterA#show ip bgp 10.13.126.1
BGP routing table entry for 10.13.126.1/32, version 788
Paths: (2 available, best #1, table default)
Flag: 0x820
Not advertised to any peer
Refresh Epoch 1
Local
10.12.100.249 from 10.12.100.249 (192.168.100.1)
Origin incomplete, metric 10, localpref 100, valid, internal, best
Refresh Epoch 1
65222 65222 65222 65222
192.168.254.1 from 192.168.254.1 (192.168.254.1)
Origin incomplete, metric 10, localpref 100, valid, external

 

Thank you.

All Router Configs.

 

Many thanks.

 

Site A - Router A

!
interface FastEthernet0/0
ip address 10.12.100.254 255.255.255.248
ip ospf 1 area 0
duplex half
!
interface FastEthernet1/0
ip address 10.12.101.2 255.255.255.252
ip ospf 1 area 0
ip ospf cost 100
duplex auto
speed auto
!
interface FastEthernet1/1
ip address 192.168.254.2 255.255.255.252
ip ospf 1 area 0
duplex auto
speed auto
!
interface FastEthernet2/0
ip address 10.10.10.1 255.255.255.252
duplex auto
speed auto
!
interface FastEthernet2/1
no ip address
shutdown
duplex auto
speed auto
!
interface FastEthernet3/0
no ip address
shutdown
duplex auto
speed auto
!
interface FastEthernet3/1
no ip address
shutdown
duplex auto
speed auto
!
router ospf 1
redistribute static metric 10 metric-type 1 subnets
redistribute bgp 65111 metric 10 metric-type 1 subnets
passive-interface FastEthernet1/1
!
router bgp 65111
bgp log-neighbor-changes
redistribute static metric 10
redistribute ospf 1 metric 10
neighbor 10.12.100.249 remote-as 65111
neighbor 10.12.100.249 next-hop-self
neighbor 192.168.254.1 remote-as 65222
neighbor 192.168.254.1 next-hop-self
neighbor 192.168.254.1 route-map AS_PRE-PEND in
!
ip forward-protocol nd
no ip http server
no ip http secure-server
!
!
ip route 10.25.10.0 255.255.255.0 10.10.10.2
!
no cdp log mismatch duplex
!
route-map AS_PRE-PEND permit 10
set as-path prepend 65222 65222 65222
!
!
!

 

Site A - Router B

!
!
interface FastEthernet0/0
ip address 10.12.100.249 255.255.255.248
ip ospf 1 area 0
duplex half
!
interface FastEthernet1/0
ip address 10.12.100.246 255.255.255.248
ip ospf 1 area 0
duplex auto
speed auto
!
interface FastEthernet1/1
ip address 192.168.100.1 255.255.255.252
duplex auto
speed auto
!
interface FastEthernet2/0
no ip address
shutdown
duplex auto
speed auto
!
interface FastEthernet2/1
no ip address
ip ospf 1 area 0
shutdown
duplex auto
speed auto
!
router ospf 1
redistribute static metric 10 metric-type 1 subnets
!
router bgp 65111
bgp log-neighbor-changes
bgp scan-time 5
redistribute static
redistribute ospf 1 metric 10 match internal external 1 external 2
neighbor 10.12.100.254 remote-as 65111
neighbor 10.12.100.254 next-hop-self
neighbor 192.168.100.2 remote-as 65002
neighbor 192.168.100.2 timers 1 3
neighbor 192.168.100.2 next-hop-self
!
ip forward-protocol nd
no ip http server
no ip http secure-server
!
!
ip route 10.25.20.0 255.255.255.0 Null0
!
no cdp log mismatch duplex
!
!
!

Site A - Router C


!
!
interface Loopback1
ip address 10.12.126.1 255.255.255.0
ip ospf 1 area 0
!
interface FastEthernet0/0
ip address 10.12.100.241 255.255.255.248
ip ospf 1 area 0
duplex half
!
interface FastEthernet1/0
ip address 10.15.101.1 255.255.255.252
ip ospf 1 area 0
ip ospf cost 101
duplex auto
speed auto
!
interface FastEthernet1/1
no ip address
shutdown
duplex auto
speed auto
!
interface FastEthernet2/0
no ip address
shutdown
duplex auto
speed auto
!
interface FastEthernet2/1
ip address 192.168.251.1 255.255.255.0
ip ospf 1 area 0
shutdown
duplex auto
speed auto
!
router ospf 1
redistribute static metric 10 metric-type 1 subnets
!
ip forward-protocol nd
no ip http server
no ip http secure-server
!
!
!
no cdp log mismatch duplex
!

 

 

 

 

Site B - Router A

!
!
!
interface FastEthernet0/0
ip address 10.13.101.2 255.255.255.252
ip ospf 1 area 0
ip ospf cost 100
duplex half
!
interface FastEthernet1/0
ip address 10.13.100.254 255.255.255.248
ip ospf 1 area 0
duplex auto
speed auto
!
interface FastEthernet1/1
ip address 192.168.254.1 255.255.255.252
ip ospf 1 area 0
duplex auto
speed auto
!
interface FastEthernet2/0
no ip address
shutdown
duplex auto
speed auto
!
interface FastEthernet2/1
no ip address
shutdown
duplex auto
speed auto
!
interface FastEthernet3/0
no ip address
shutdown
duplex auto
speed auto
!
interface FastEthernet3/1
no ip address
shutdown
duplex auto
speed auto
!
router ospf 1
redistribute bgp 65222 metric 10 metric-type 1 subnets
passive-interface FastEthernet1/1
!
router bgp 65222
bgp log-neighbor-changes
redistribute ospf 1 metric 10
neighbor 10.13.100.249 remote-as 65222
neighbor 10.13.100.249 next-hop-self
neighbor 192.168.254.2 remote-as 65111
neighbor 192.168.254.2 next-hop-self
neighbor 192.168.254.2 route-map AS_PRE-PEND in
!
ip forward-protocol nd
no ip http server
no ip http secure-server
!
!
!
no cdp log mismatch duplex
!
route-map AS_PRE-PEND permit 10
set as-path prepend 65111 65111 65111
!

 

Site B - Router B

!
!
!
!
interface FastEthernet0/0
ip address 192.168.101.1 255.255.255.252
duplex half
!
interface FastEthernet1/0
ip address 10.13.100.249 255.255.255.248
ip ospf 1 area 0
duplex auto
speed auto
!
interface FastEthernet1/1
ip address 10.13.100.246 255.255.255.248
ip ospf 1 area 0
duplex auto
speed auto
!
interface FastEthernet2/0
no ip address
shutdown
duplex auto
speed auto
!
interface FastEthernet2/1
no ip address
ip ospf 1 area 0
shutdown
duplex auto
speed auto
!
router ospf 1
redistribute bgp 65222 metric 10 metric-type 1 subnets
!
router bgp 65222
bgp log-neighbor-changes
bgp scan-time 5
redistribute ospf 1 metric 10 match internal external 1 external 2
neighbor 10.13.100.254 remote-as 65222
neighbor 10.13.100.254 timers 1 3
neighbor 10.13.100.254 next-hop-self
neighbor 192.168.101.2 remote-as 65002
neighbor 192.168.101.2 timers 1 3
neighbor 192.168.101.2 next-hop-self
!
ip forward-protocol nd
no ip http server
no ip http secure-server
!

 

Site B - Router C

!
!
!
!
interface Loopback1
ip address 10.13.126.1 255.255.255.0
ip ospf 1 area 0
!
interface FastEthernet0/0
ip address 10.13.101.1 255.255.255.252
ip ospf 1 area 0
ip ospf cost 101
duplex half
!
interface FastEthernet1/0
ip address 10.13.100.241 255.255.255.248
ip ospf 1 area 0
duplex auto
speed auto
!
interface FastEthernet1/1
no ip address
shutdown
duplex auto
speed auto
!
interface FastEthernet2/0
no ip address
shutdown
duplex auto
speed auto
!
interface FastEthernet2/1
ip address 192.168.251.2 255.255.255.0
ip ospf 1 area 0
shutdown
duplex auto
speed auto
!
router ospf 1
!
ip forward-protocol nd
no ip http server
no ip http secure-server
!

 

 

 

Hello

After reviewing your topology and the configuration you posted a few things stand out to me-

 

Firstly I see you have manually set bgp scan time values down to 5 secs which is very low and can increase a lot of burden on your rtrs and you have only done this on site B rtrs of each site

 

Also you have half duplex interfaces which seem to be connected towards your ebgp peers which isn't good as this can cause connectivity issues with routing protocols especially if there is a lot of bidirectional traffic and even more so with bgp being tcp driven.

 

bgp next hop-self is applied between site a and b ebgp peers which isn't applicable here I would say they should be applied towards any internal Ibgp peers and between rtr a and b in each site only

 

Rtr c has static routes which being redistributed into ospf as external networks can you confirm if they are indeed external to that router-

 

Going forward I would suggest possibly looking into the above especially the bgp scan timers and the half duplex interfaces and maybe even think about advertising conditionl default routes internally into ospf  with preference on metric type instead of redistrubing bgp into your igp


Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul


Hi Paul, 

 

Thanks for your message, please see my comments below.



@paul driver wrote:

Hello

After reviewing your topology and the configuration you posted a few things stand out to me-

 

Firstly I see you have manually set bgp scan time values down to 5 secs which is very low and can increase a lot of burden on your rtrs and you have only done this on site B rtrs of each site

 

- I have now removed the bgp scan time and left it as default, thanks.

 

Also you have half duplex interfaces which seem to be connected towards your ebgp peers which isn't good as this can cause connectivity issues with routing protocols especially if there is a lot of bidirectional traffic and even more so with bgp being tcp driven.

 

- I have performed a debug and ping and could not see any packet drops, maybe there is something in BGP which doesn't like half-duplex. I have now hard coded all the links to 100/Full, thank you.

 

bgp next hop-self is applied between site a and b ebgp peers which isn't applicable here I would say they should be applied towards any internal Ibgp peers and between rtr a and b in each site only

 

- I have not removed 'next-hop-self' on all eBGP neighbours. 

 

Rtr c has static routes which being redistributed into ospf as external networks can you confirm if they are indeed external to that router-

 

- We have some legacy network which is connected via Router C, only way to reach this network is via static. However, other parts of the network need to understand how they can reach this network. When redistributing network into OSPF I always tend to place then as E1, habit, I guess.

 

Going forward I would suggest possibly looking into the above especially the bgp scan timers and the half duplex interfaces and maybe even think about advertising conditionl default routes internally into ospf  with preference on metric type instead of redistrubing bgp into your igp

 

- I have changed the links to 100/Full and removed the bgp scan timer, appreciate the assistance. We need the routes which come into BGP to be seen in Router C and vice versa. Paul, after making the recommended changes when the link between the MPLS AS65002 and Router B in Site B is down, I'm still seeing route flaps between Router A and Router B in Site A for the network behind Router C in Site B, 10.13.126.1.

 


I have taken some debug on both Router A and Router B, to understand what is happening. It would seem, after reading the debug logs that: -

 

  1. Network 10.13.126.1 is advertised to Router A in Site A from Router A in Site B via eBGP
  2. Router A in Site A learns this router and places it into the RIB as eBGP with next-hop of 192.168.254.1, Router A Site B
  3. Router A has mutual redistribution, therefore network is also passed to Router B via OSPF
  4. Router B now has a route to 10.13.126.1 via Router A using OSPF
  5. Router B has mutual redistribution, therefore network is also passed to Router A via iBGP and OSPF is less prefered
  6. Router B in Site A then redistributes this route into BGP where Router A in Site learns is via Router B in Site A as with metric of 200
  7. This process repeats roughly every five seconds

Router A route for 10.13.126.1 flaps between iBGP to Router B or flaps to Router A Site A (correct route) via eBGP. Where as Router B in Site A flaps between iBGP and OSPF towards Router A in Site A.

 

I would really appreciate if someone could check the debug logs, I have tried to keep timestamps as accurate as possible...

The below commands were executed on both Router A and B in Site A

 

show clock

debug ip ospf spf
debug ip routing detail
debug ip bgp updates

 

Thanks in advance. 

 

Router A Site A

 

RouterA#show clock
*10:09:46.515 UTC Sun Mar 17 2019
RouterA#
RouterA#debug ip ospf spf
OSPF SPF debugging is on
OSPF SPF intra debugging is on
OSPF SPF inter debugging is on
OSPF SPF external debugging is on
RouterA#debug ip routing detail
IP routing debugging is on (detailed)
RouterA#debug ip bgp updates
BGP updates debugging is on for address family: IPv4 Unicast
RouterA#
*Mar 17 10:09:49.939: BGP(0): 10.12.100.249 rcv UPDATE about 10.13.100.240/29 -- withdrawn
*Mar 17 10:09:49.943: BGP(0): Revise route installing 1 of 1 routes for 10.13.100.240/29 -> 192.168.254.1(global) to main IP table
*Mar 17 10:09:49.943: RT: updating bgp 10.13.100.240/29 (0x0):
via 192.168.254.1 1048577

 

*Mar 17 10:09:49.947: RT: closer admin distance for 10.13.100.240, flushing 1 routes
*Mar 17 10:09:49.951: RT: add 10.13.100.240/29 via 192.168.254.1, bgp metric [20/10]
*Mar 17 10:09:49.967: BGP(0): 10.12.100.249 NEXT_HOP is set to self for net 10.13.100.240/29,
*Mar 17 10:09:49.967: BGP(0): (base) 10.12.100.249 send UPDATE (format) 10.13.100.240/29, next 10.12.100.254, metric 10, path 65222 65222 65222 65222
*Mar 17 10:09:49.991: BGP(0): 10.12.100.249 rcv UPDATE about 10.13.100.248/29 -- withdrawn
*Mar 17 10:09:49.995: BGP(0): 10.12.100.249 rcv UPDATE about 10.13.101.0/30 -- withdrawn
*Mar 17 10:09:49.995: BGP(0): 10.12.100.249 rcv UPDATE about 10.13.126.1/
RouterA#32 -- withdrawn
*Mar 17 10:09:49.999: BGP(0): Revise route installing 1 of 1 routes for 10.13.100.248/29 -> 192.168.254.1(global) to main IP table
*Mar 17 10:09:49.999: RT: updating bgp 10.13.100.248/29 (0x0):
via 192.168.254.1 1048577

*Mar 17 10:09:50.003: RT: closer admin distance for 10.13.100.248, flushing 1 routes
*Mar 17 10:09:50.003: RT: add 10.13.100.248/29 via 192.168.254.1, bgp metric [20/0]
*Mar 17 10:09:50.003: BGP(0): Revise route installing 1 of 1 routes for 10.13.101.0/30 -> 192.168.254.1(global) to main IP table
*Mar 17 10:09:50.003: RT: updating bgp 10.13.101.0/30 (0x0):
via 192.168.254.1 1048577

*Mar 17 10:09:50.003: RT: closer admin distance for 10.13.101.0, flushing 1 routes
*Mar 17 10:09:50.003: RT: add 10.13.101.0/30 via 192.168.254.1, bgp metric [20/0]
*Mar 17 10:09:50.003: BGP(0): Revise route installing 1 of 1 routes for 10.13.126.1/32 -> 192.168.254.1(global) to main IP table
*Mar 17 10:09:50.003: RT: updating bgp 10.13.126.1/32 (0
RouterA#x0):
via 192.168.254.1 1048577

*Mar 17 10:09:50.003: RT: closer admin distance for 10.13.126.1, flushing 1 routes
*Mar 17 10:09:50.007: RT: add 10.13.126.1/32 via 192.168.254.1, bgp metric [20/10]
*Mar 17 10:09:50.007: BGP(0): 10.12.100.249 NEXT_HOP is set to self for net 10.13.100.248/29,
*Mar 17 10:09:50.007: BGP(0): (base) 10.12.100.249 send UPDATE (format) 10.13.100.248/29, next 10.12.100.254, metric 0, path 65222 65222 65222 65222
*Mar 17 10:09:50.007: BGP(0): 10.12.100.249 NEXT_HOP is set to self for net 10.13.101.0/30,
*Mar 17 10:09:50.007: BGP(0): 10.12.100.249 NEXT_HOP is set to self for net 10.13.126.1/32,
*Mar 17 10:09:50.007: BGP(0): (base) 10.12.100.249 send UPDATE (format) 10.13.126.1/32, next 10.12.100.254, metric 10, path 65222 65222 65222 65222
RouterA#
*Mar 17 10:09:54.979: BGP(0): 10.12.100.249 rcvd UPDATE w/ attr: nexthop 10.12.100.249, origin ?, localpref 100, metric 10
*Mar 17 10:09:54.983: BGP(0): 10.12.100.249 rcvd 10.13.100.240/29
*Mar 17 10:09:54.987: BGP(0): 10.12.100.249 rcvd UPDATE w/ attr: nexthop 10.12.100.249, origin ?, localpref 100, metric 10
*Mar 17 10:09:54.991: BGP(0): 10.12.100.249 rcvd 10.13.100.248/29
*Mar 17 10:09:54.995: BGP(0): 10.12.100.249 rcvd 10.13.101.0/30
*Mar 17 10:09:54.995: BGP(0): 10.12.100.249 rcvd 10.13.126.1/32
*Mar 17 10:09:54.999: BGP(0): Revise route installing 1 of 1 routes for 10.13.100.240/29 -> 10.12.100.249(global) to main IP table
*Mar 17 10:09:54.999: RT: updating bgp 10.13.100.240/29 (0x0):
via 10.12.100.249 1048577

*Mar 17 10:09:54.999: RT: closer admin distance for 10.13.100.240, flushing 1 routes
*Mar 17 10:09:54.999: RT: add 10.13.100.240/29 via 10.12.100.249, bgp metric [200/10]
*Mar 17 10:09:54.999: BGP(0): Revise route installing 1 of 1 routes for 10.13.100
RouterA#.248/29 -> 10.12.100.249(global) to main IP table
*Mar 17 10:09:54.999: RT: updating bgp 10.13.100.248/29 (0x0):
via 10.12.100.249 1048577

*Mar 17 10:09:54.999: RT: closer admin distance for 10.13.100.248, flushing 1 routes
*Mar 17 10:09:54.999: RT: add 10.13.100.248/29 via 10.12.100.249, bgp metric [200/10]
*Mar 17 10:09:54.999: BGP(0): Revise route installing 1 of 1 routes for 10.13.101.0/30 -> 10.12.100.249(global) to main IP table
*Mar 17 10:09:54.999: RT: updating bgp 10.13.101.0/30 (0x0):
via 10.12.100.249 1048577

*Mar 17 10:09:55.003: RT: closer admin distance for 10.13.101.0, flushing 1 routes
*Mar 17 10:09:55.003: RT: add 10.13.101.0/30 via 10.12.100.249, bgp metric [200/10]
*Mar 17 10:09:55.003: BGP(0): Revise route installing 1 of 1 routes for 10.13.126.1/32 -> 10.12.100.249(global) to main IP table
*Mar 17 10:09:55.003: RT: updating bgp 10.13.126.1/32 (0x0):
via 10.12.100.249 1048577

*Mar 17 10:09:55.003: RT: closer admin distance for 1
RouterA#0.13.126.1, flushing 1 routes
*Mar 17 10:09:55.003: RT: add 10.13.126.1/32 via 10.12.100.249, bgp metric [200/10]
*Mar 17 10:09:55.003: BGP(0): (base) 10.12.100.249 send unreachable (format) 10.13.100.240/29
RouterA#
*Mar 17 10:09:59.939: BGP(0): 10.12.100.249 rcv UPDATE about 10.13.100.240/29 -- withdrawn
*Mar 17 10:09:59.939: BGP(0): Revise route installing 1 of 1 routes for 10.13.100.240/29 -> 192.168.254.1(global) to main IP table
*Mar 17 10:09:59.943: RT: updating bgp 10.13.100.240/29 (0x0):
via 192.168.254.1 1048577

*Mar 17 10:09:59.947: RT: closer admin distance for 10.13.100.240, flushing 1 routes
*Mar 17 10:09:59.951: RT: add 10.13.100.240/29 via 192.168.254.1, bgp metric [20/10]
*Mar 17 10:09:59.951: BGP(0): 10.12.100.249 NEXT_HOP is set to self for net 10.13.100.240/29,
*Mar 17 10:09:59.955: BGP(0): (base) 10.12.100.249 send UPDATE (format) 10.13.100.240/29, next 10.12.100.254, metric 10, path 65222 65222 65222 65222
*Mar 17 10:09:59.979: BGP(0): 10.12.100.249 rcv UPDATE about 10.13.100.248/29 -- withdrawn
*Mar 17 10:09:59.979: BGP(0): 10.12.100.249 rcv UPDATE about 10.13.101.0/30 -- withdrawn
*Mar 17 10:09:59.983: BGP(0): 10.12.100.249 rcv UPDATE about 10.13.126.1/
RouterA#32 -- withdrawn
*Mar 17 10:09:59.983: BGP(0): Revise route installing 1 of 1 routes for 10.13.100.248/29 -> 192.168.254.1(global) to main IP table
*Mar 17 10:09:59.983: RT: updating bgp 10.13.100.248/29 (0x0):
via 192.168.254.1 1048577

*Mar 17 10:09:59.983: RT: closer admin distance for 10.13.100.248, flushing 1 routes
*Mar 17 10:09:59.983: RT: add 10.13.100.248/29 via 192.168.254.1, bgp metric [20/0]
*Mar 17 10:09:59.983: BGP(0): Revise route installing 1 of 1 routes for 10.13.101.0/30 -> 192.168.254.1(global) to main IP table
*Mar 17 10:09:59.983: RT: updating bgp 10.13.101.0/30 (0x0):
via 192.168.254.1 1048577

*Mar 17 10:09:59.983: RT: closer admin distance for 10.13.101.0, flushing 1 routes
*Mar 17 10:09:59.983: RT: add 10.13.101.0/30 via 192.168.254.1, bgp metric [20/0]
*Mar 17 10:09:59.983: BGP(0): Revise route installing 1 of 1 routes for 10.13.126.1/32 -> 192.168.254.1(global) to main IP table
*Mar 17 10:09:59.983: RT: updating bgp 10.13.126.1/32 (0
RouterA#x0):
via 192.168.254.1 1048577

*Mar 17 10:09:59.983: RT: closer admin distance for 10.13.126.1, flushing 1 routes
*Mar 17 10:09:59.983: RT: add 10.13.126.1/32 via 192.168.254.1, bgp metric [20/10]
*Mar 17 10:09:59.987: BGP(0): 10.12.100.249 NEXT_HOP is set to self for net 10.13.100.248/29,
*Mar 17 10:09:59.987: BGP(0): (base) 10.12.100.249 send UPDATE (format) 10.13.100.248/29, next 10.12.100.254, metric 0, path 65222 65222 65222 65222
*Mar 17 10:09:59.987: BGP(0): 10.12.100.249 NEXT_HOP is set to self for net 10.13.101.0/30,
*Mar 17 10:09:59.987: BGP(0): 10.12.100.249 NEXT_HOP is set to self for net 10.13.126.1/32,
*Mar 17 10:09:59.987: BGP(0): (base) 10.12.100.249 send UPDATE (format) 10.13.126.1/32, next 10.12.100.254, metric 10, path 65222 65222 65222 65222
*Mar 17 10:10:00.787: BGP(0): 192.168.254.1 rcvd UPDATE w/ attr: nexthop 192.168.254.1, origin ?, merged path 65222, AS_PATH
*Mar 17 10:10:00.791: BGP(0): 192.168.254.1 rcvd 10.12.100.240/29...duplicate ig
RouterA#nored
*Mar 17 10:10:00.795: BGP(0): 192.168.254.1 rcvd 10.12.100.248/29...duplicate ignored
*Mar 17 10:10:00.795: BGP(0): 192.168.254.1 rcvd 10.12.101.0/30...duplicate ignored
*Mar 17 10:10:00.799: BGP(0): 192.168.254.1 rcvd 10.12.126.1/32...duplicate ignored
*Mar 17 10:10:00.799: BGP(0): 192.168.254.1 rcvd 10.15.101.0/30...duplicate ignored
*Mar 17 10:10:00.799: BGP(0): 192.168.254.1 rcvd 10.25.10.0/24...duplicate ignored
*Mar 17 10:10:00.799: BGP(0): 192.168.254.1 rcvd 10.25.20.0/24...duplicate ignored
*Mar 17 10:10:00.799: BGP(0): 192.168.254.1 rcvd 10.25.30.0/24...duplicate ignored
RouterA#
*Mar 17 10:10:04.967: BGP(0): 10.12.100.249 rcvd UPDATE w/ attr: nexthop 10.12.100.249, origin ?, localpref 100, metric 10
*Mar 17 10:10:04.971: BGP(0): 10.12.100.249 rcvd 10.13.100.240/29
*Mar 17 10:10:04.971: BGP(0): Revise route installing 1 of 1 routes for 10.13.100.240/29 -> 10.12.100.249(global) to main IP table
*Mar 17 10:10:04.971: RT: updating bgp 10.13.100.240/29 (0x0):
via 10.12.100.249 1048577

*Mar 17 10:10:04.971: RT: closer admin distance for 10.13.100.240, flushing 1 routes
*Mar 17 10:10:04.971: RT: add 10.13.100.240/29 via 10.12.100.249, bgp metric [200/10]
*Mar 17 10:10:04.971: BGP(0): (base) 10.12.100.249 send unreachable (format) 10.13.100.240/29
*Mar 17 10:10:04.979: BGP(0): 10.12.100.249 rcvd UPDATE w/ attr: nexthop 10.12.100.249, origin ?, localpref 100, metric 10
*Mar 17 10:10:04.979: BGP(0): 10.12.100.249 rcvd 10.13.100.248/29
*Mar 17 10:10:04.979: BGP(0): 10.12.100.249 rcvd 10.13.101.0/30
*Mar 17 10:10:04.979: BGP(0): 10.12.100.249 rcvd 10
RouterA#.13.126.1/32
*Mar 17 10:10:04.979: BGP(0): Revise route installing 1 of 1 routes for 10.13.100.248/29 -> 10.12.100.249(global) to main IP table
*Mar 17 10:10:04.979: RT: updating bgp 10.13.100.248/29 (0x0):
via 10.12.100.249 1048577

*Mar 17 10:10:04.983: RT: closer admin distance for 10.13.100.248, flushing 1 routes
*Mar 17 10:10:04.983: RT: add 10.13.100.248/29 via 10.12.100.249, bgp metric [200/10]
*Mar 17 10:10:04.983: BGP(0): Revise route installing 1 of 1 routes for 10.13.101.0/30 -> 10.12.100.249(global) to main IP table
*Mar 17 10:10:04.983: RT: updating bgp 10.13.101.0/30 (0x0):
via 10.12.100.249 1048577

*Mar 17 10:10:04.983: RT: closer admin distance for 10.13.101.0, flushing 1 routes
*Mar 17 10:10:04.983: RT: add 10.13.101.0/30 via 10.12.100.249, bgp metric [200/10]
*Mar 17 10:10:04.983: BGP(0): Revise route installing 1 of 1 routes for 10.13.126.1/32 -> 10.12.100.249(global) to main IP table
*Mar 17 10:10:04.983: RT: updating bgp 10.13.126.1/32 (
RouterA#0x0):
via 10.12.100.249 1048577

*Mar 17 10:10:04.983: RT: closer admin distance for 10.13.126.1, flushing 1 routes
*Mar 17 10:10:04.983: RT: add 10.13.126.1/32 via 10.12.100.249, bgp metric [200/10]
*Mar 17 10:10:04.983: BGP(0): (base) 10.12.100.249 send unreachable (format) 10.13.100.248/29
RouterA#
*Mar 17 10:10:09.959: BGP(0): 10.12.100.249 rcv UPDATE about 10.13.100.240/29 -- withdrawn
*Mar 17 10:10:09.963: BGP(0): Revise route installing 1 of 1 routes for 10.13.100.240/29 -> 192.168.254.1(global) to main IP table
*Mar 17 10:10:09.963: RT: updating bgp 10.13.100.240/29 (0x0):
via 192.168.254.1 1048577

*Mar 17 10:10:09.967: RT: closer admin distance for 10.13.100.240, flushing 1 routes
*Mar 17 10:10:09.967: RT: add 10.13.100.240/29 via 192.168.254.1, bgp metric [20/10]
*Mar 17 10:10:09.967: BGP(0): 10.12.100.249 NEXT_HOP is set to self for net 10.13.100.240/29,
*Mar 17 10:10:09.967: BGP(0): (base) 10.12.100.249 send UPDATE (format) 10.13.100.240/29, next 10.12.100.254, metric 10, path 65222 65222 65222 65222
*Mar 17 10:10:09.991: BGP(0): 10.12.100.249 rcv UPDATE about 10.13.100.248/29 -- withdrawn
*Mar 17 10:10:09.991: BGP(0): 10.12.100.249 rcv UPDATE about 10.13.101.0/30 -- withdrawn
*Mar 17 10:10:09.995: BGP(0): 10.12.100.249 rcv UPDATE about 10.13.126.1/
RouterA#32 -- withdrawn
*Mar 17 10:10:09.999: BGP(0): Revise route installing 1 of 1 routes for 10.13.100.248/29 -> 192.168.254.1(global) to main IP table
*Mar 17 10:10:09.999: RT: updating bgp 10.13.100.248/29 (0x0):
via 192.168.254.1 1048577

*Mar 17 10:10:10.003: RT: closer admin distance for 10.13.100.248, flushing 1 routes
*Mar 17 10:10:10.007: RT: add 10.13.100.248/29 via 192.168.254.1, bgp metric [20/0]
*Mar 17 10:10:10.007: BGP(0): Revise route installing 1 of 1 routes for 10.13.101.0/30 -> 192.168.254.1(global) to main IP table
*Mar 17 10:10:10.007: RT: updating bgp 10.13.101.0/30 (0x0):
via 192.168.254.1 1048577

*Mar 17 10:10:10.007: RT: closer admin distance for 10.13.101.0, flushing 1 routes
*Mar 17 10:10:10.007: RT: add 10.13.101.0/30 via 192.168.254.1, bgp metric [20/0]
*Mar 17 10:10:10.007: BGP(0): Revise route installing 1 of 1 routes for 10.13.126.1/32 -> 192.168.254.1(global) to main IP table
*Mar 17 10:10:10.007: RT: updating bgp 10.13.126.1/32 (0
RouterA#x0):
via 192.168.254.1 1048577

*Mar 17 10:10:10.007: RT: closer admin distance for 10.13.126.1, flushing 1 routes
*Mar 17 10:10:10.007: RT: add 10.13.126.1/32 via 192.168.254.1, bgp metric [20/10]
*Mar 17 10:10:10.007: BGP(0): 10.12.100.249 NEXT_HOP is set to self for net 10.13.100.248/29,
*Mar 17 10:10:10.007: BGP(0): (base) 10.12.100.249 send UPDATE (format) 10.13.100.248/29, next 10.12.100.254, metric 0, path 65222 65222 65222 65222
*Mar 17 10:10:10.011: BGP(0): 10.12.100.249 NEXT_HOP is set to self for net 10.13.101.0/30,
*Mar 17 10:10:10.011: BGP(0): 10.12.100.249 NEXT_HOP is set to self for net 10.13.126.1/32,
*Mar 17 10:10:10.011: BGP(0): (base) 10.12.100.249 send UPDATE (format) 10.13.126.1/32, next 10.12.100.254, metric 10, path 65222 65222 65222 65222
RouterA#undebug all
All possible debugging has been turned off
RouterA#

 

Router B Site A

 

 

RouterB#show clock
*10:09:47.275 UTC Sun Mar 17 2019
RouterB#
RouterB#debug ip ospf spf
OSPF SPF debugging is on
OSPF SPF intra debugging is on
OSPF SPF inter debugging is on
OSPF SPF external debugging is on
RouterB#debug ip routing detail
IP routing debugging is on (detailed)
RouterB#debug ip bgp updates
BGP updates debugging is on for address family: IPv4 Unicast
RouterB#
*Mar 17 10:09:50.055: OSPF-1 SPF : Detect MAXAGE in LSA type 5, LS ID 10.13.100.240, from 192.168.254.2
*Mar 17 10:09:50.055: OSPF-1 SPF : Detect generic change in LSA type 5, LSID 10.13.100.240, from 192.168.254.2 area 0
*Mar 17 10:09:50.059: OSPF-1 SPF : Schedule partial SPF type 5, LSID 10.13.100.240, adv_rtr 192.168.254.2 area dummy area
*Mar 17 10:09:50.063: OSPF-1 SPF : Service partial SPF, spf instance 2112, 0/1/0
*Mar 17 10:09:50.063: OSPF-1 INTER: Process partial summary spf queue
*Mar 17 10:09:50.063: OSPF-1 EXTER: Process partial external spf queue
*Mar 17 10:09:50.063: OSPF-1 EXTER: Process partial spfQ: type 5, LSID 10.13.100.240, mask 255.255.255.248, adv_rtr 192.168.254.2, age 3600, seq 0x800003B1, area dummy area
*Mar 17 10:09:50.063: OSPF-1 EXTER: Start partial processing Type 5 External LSA 10.13.100.240, mask 255.255.255.248
*Mar 17 10:09:50.063: OSPF-1 EXTER: adv_rtr 192.168.254.2, age 3600, seq 0x800003B1, metric 16777215, metric-type 1, fw-addr 1
RouterB#0.12.100.249
*Mar 17 10:09:50.063: RT: del 10.13.100.240 via 10.12.100.254, ospf metric [110/11]
*Mar 17 10:09:50.063: RT: delete subnet route to 10.13.100.240/29
*Mar 17 10:09:50.063: OSPF-1 EXTER: Deleted external route 10.13.100.240/255.255.255.248
*Mar 17 10:09:50.063: OSPF-1 EXTER: Process partial nssa spf queue
*Mar 17 10:09:50.067: BGP(0): route 10.13.100.240/29 down
*Mar 17 10:09:50.067: BGP(0): no valid path for 10.13.100.240/29
*Mar 17 10:09:50.067: BGP: topo global:IPv4 Unicast:base Remove_fwdroute for 10.13.100.240/29
*Mar 17 10:09:50.067: BGP(0): (base) 10.12.100.254 send unreachable (format) 10.13.100.240/29
*Mar 17 10:09:50.107: OSPF-1 SPF : Detect MAXAGE in LSA type 5, LS ID 10.13.100.248, from 192.168.254.2
*Mar 17 10:09:50.107: OSPF-1 SPF : Detect generic change in LSA type 5, LSID 10.13.100.248, from 192.168.254.2 area 0
*Mar 17 10:09:50.107: OSPF-1 SPF : Schedule partial SPF type 5, LSID 10.13.100.248, adv_rtr 192.168.254.2 area dummy area
*Mar 17
RouterB# 10:09:50.111: OSPF-1 SPF : Detect MAXAGE in LSA type 5, LS ID 10.13.101.0, from 192.168.254.2
*Mar 17 10:09:50.111: OSPF-1 SPF : Detect generic change in LSA type 5, LSID 10.13.101.0, from 192.168.254.2 area 0
*Mar 17 10:09:50.111: OSPF-1 SPF : Schedule partial SPF type 5, LSID 10.13.101.0, adv_rtr 192.168.254.2 area dummy area
*Mar 17 10:09:50.111: OSPF-1 SPF : Detect MAXAGE in LSA type 5, LS ID 10.13.126.1, from 192.168.254.2
*Mar 17 10:09:50.111: OSPF-1 SPF : Detect generic change in LSA type 5, LSID 10.13.126.1, from 192.168.254.2 area 0
*Mar 17 10:09:50.111: OSPF-1 SPF : Schedule partial SPF type 5, LSID 10.13.126.1, adv_rtr 192.168.254.2 area dummy area
*Mar 17 10:09:50.111: OSPF-1 SPF : Service partial SPF, spf instance 2113, 0/3/0
*Mar 17 10:09:50.111: OSPF-1 INTER: Process partial summary spf queue
*Mar 17 10:09:50.111: OSPF-1 EXTER: Process partial external spf queue
*Mar 17 10:09:50.111: OSPF-1 EXTER: Process partial spfQ: type 5, LSID 10.13.100.248, mask
RouterB# 255.255.255.248, adv_rtr 192.168.254.2, age 3600, seq 0x800003B1, area dummy area
*Mar 17 10:09:50.111: OSPF-1 EXTER: Start partial processing Type 5 External LSA 10.13.100.248, mask 255.255.255.248
*Mar 17 10:09:50.111: OSPF-1 EXTER: adv_rtr 192.168.254.2, age 3600, seq 0x800003B1, metric 16777215, metric-type 1, fw-addr 10.12.100.249
*Mar 17 10:09:50.111: RT: del 10.13.100.248 via 10.12.100.254, ospf metric [110/11]
*Mar 17 10:09:50.111: RT: delete subnet route to 10.13.100.248/29
*Mar 17 10:09:50.111: OSPF-1 EXTER: Deleted external route 10.13.100.248/255.255.255.248
*Mar 17 10:09:50.111: OSPF-1 EXTER: Process partial spfQ: type 5, LSID 10.13.101.0, mask 255.255.255.252, adv_rtr 192.168.254.2, age 3600, seq 0x800003B1, area dummy area
*Mar 17 10:09:50.111: OSPF-1 EXTER: Start partial processing Type 5 External LSA 10.13.101.0, mask 255.255.255.252
*Mar 17 10:09:50.111: OSPF-1 EXTER: adv_rtr 192.168.254.2, age 3600, seq 0x800003B1, metric 16777215, metric-type 1, fw-a
RouterB#ddr 10.12.100.249
*Mar 17 10:09:50.111: RT: del 10.13.101.0 via 10.12.100.254, ospf metric [110/11]
*Mar 17 10:09:50.111: RT: delete subnet route to 10.13.101.0/30
*Mar 17 10:09:50.111: OSPF-1 EXTER: Deleted external route 10.13.101.0/255.255.255.252
*Mar 17 10:09:50.111: OSPF-1 EXTER: Process partial spfQ: type 5, LSID 10.13.126.1, mask 255.255.255.255, adv_rtr 192.168.254.2, age 3600, seq 0x800003B1, area dummy area
*Mar 17 10:09:50.111: OSPF-1 EXTER: Start partial processing Type 5 External LSA 10.13.126.1, mask 255.255.255.255
*Mar 17 10:09:50.111: OSPF-1 EXTER: adv_rtr 192.168.254.2, age 3600, seq 0x800003B1, metric 16777215, metric-type 1, fw-addr 10.12.100.249
*Mar 17 10:09:50.111: RT: del 10.13.126.1 via 10.12.100.254, ospf metric [110/11]
*Mar 17 10:09:50.111: RT: delete subnet route to 10.13.126.1/32
*Mar 17 10:09:50.111: OSPF-1 EXTER: Deleted external route 10.13.126.1/255.255.255.255
*Mar 17 10:09:50.111: OSPF-1 EXTER: Process partial nssa spf queue
*Mar 1
RouterB#7 10:09:50.115: BGP(0): 10.12.100.254 rcvd UPDATE w/ attr: nexthop 10.12.100.254, origin ?, localpref 100, metric 10, merged path 65222 65222 65222 65222, AS_PATH
*Mar 17 10:09:50.115: BGP(0): 10.12.100.254 rcvd 10.13.100.240/29
*Mar 17 10:09:50.115: BGP(0): Revise route installing 1 of 1 routes for 10.13.100.240/29 -> 10.12.100.254(global) to main IP table
*Mar 17 10:09:50.119: RT: updating bgp 10.13.100.240/29 (0x0):
via 10.12.100.254 1048577

*Mar 17 10:09:50.119: RT: add 10.13.100.240/29 via 10.12.100.254, bgp metric [200/10]
*Mar 17 10:09:50.119: BGP(0): route 10.13.100.248/29 down
*Mar 17 10:09:50.119: BGP(0): no valid path for 10.13.100.248/29
*Mar 17 10:09:50.119: BGP(0): route 10.13.101.0/30 down
*Mar 17 10:09:50.119: BGP(0): no valid path for 10.13.101.0/30
*Mar 17 10:09:50.119: BGP(0): route 10.13.126.1/32 down
*Mar 17 10:09:50.119: BGP(0): no valid path for 10.13.126.1/32
*Mar 17 10:09:50.119: BGP: topo global:IPv4 Unicast:base Remove_fwdroute for 10.13
RouterB#.100.248/29
*Mar 17 10:09:50.123: BGP: topo global:IPv4 Unicast:base Remove_fwdroute for 10.13.101.0/30
*Mar 17 10:09:50.123: BGP: topo global:IPv4 Unicast:base Remove_fwdroute for 10.13.126.1/32
*Mar 17 10:09:50.123: BGP(0): (base) 10.12.100.254 send unreachable (format) 10.13.100.248/29
*Mar 17 10:09:50.135: BGP(0): 10.12.100.254 rcvd UPDATE w/ attr: nexthop 10.12.100.254, origin ?, localpref 100, metric 0, merged path 65222 65222 65222 65222, AS_PATH
*Mar 17 10:09:50.139: BGP(0): 10.12.100.254 rcvd 10.13.100.248/29
*Mar 17 10:09:50.139: BGP(0): 10.12.100.254 rcvd 10.13.101.0/30
*Mar 17 10:09:50.139: BGP(0): 10.12.100.254 rcvd UPDATE w/ attr: nexthop 10.12.100.254, origin ?, localpref 100, metric 10, merged path 65222 65222 65222 65222, AS_PATH
*Mar 17 10:09:50.143: BGP(0): 10.12.100.254 rcvd 10.13.126.1/32
*Mar 17 10:09:50.143: BGP(0): Revise route installing 1 of 1 routes for 10.13.100.248/29 -> 10.12.100.254(global) to main IP table
*Mar 17 10:09:50.143: RT: updating
RouterB#bgp 10.13.100.248/29 (0x0):
via 10.12.100.254 1048577

*Mar 17 10:09:50.143: RT: add 10.13.100.248/29 via 10.12.100.254, bgp metric [200/0]
*Mar 17 10:09:50.143: BGP(0): Revise route installing 1 of 1 routes for 10.13.101.0/30 -> 10.12.100.254(global) to main IP table
*Mar 17 10:09:50.143: RT: updating bgp 10.13.101.0/30 (0x0):
via 10.12.100.254 1048577

*Mar 17 10:09:50.143: RT: add 10.13.101.0/30 via 10.12.100.254, bgp metric [200/0]
*Mar 17 10:09:50.143: BGP(0): Revise route installing 1 of 1 routes for 10.13.126.1/32 -> 10.12.100.254(global) to main IP table
*Mar 17 10:09:50.143: RT: updating bgp 10.13.126.1/32 (0x0):
via 10.12.100.254 1048577

*Mar 17 10:09:50.143: RT: add 10.13.126.1/32 via 10.12.100.254, bgp metric [200/10]
*Mar 17 10:09:55.043: OSPF-1 SPF : Schedule partial SPF type 5, LSID 10.13.100.240, adv_rtr 192.168.254.2 area dummy area
*Mar 17 10:09:55.047: OSPF-1 SPF : Service partial SPF, spf instance 2114, 0/1/0
*Mar 17 10:09:55.0
RouterB#47: OSPF-1 INTER: Process partial summary spf queue
*Mar 17 10:09:55.051: OSPF-1 EXTER: Process partial external spf queue
*Mar 17 10:09:55.051: OSPF-1 EXTER: Process partial spfQ: type 5, LSID 10.13.100.240, mask 255.255.255.248, adv_rtr 192.168.254.2, age 1, seq 0x800003B2, area dummy area
*Mar 17 10:09:55.055: OSPF-1 EXTER: Start partial processing Type 5 External LSA 10.13.100.240, mask 255.255.255.248
*Mar 17 10:09:55.055: OSPF-1 EXTER: adv_rtr 192.168.254.2, age 1, seq 0x800003B2, metric 10, metric-type 1, fw-addr 0.0.0.0
*Mar 17 10:09:55.059: OSPF-1 SPF : Add better path to LSA ID 10.13.100.240, gateway 10.12.100.254, dist 11
*Mar 17 10:09:55.059: OSPF-1 SPF : Add path: next-hop 10.12.100.254, interface FastEthernet0/0
*Mar 17 10:09:55.059: OSPF-1 EXTER: Route update succeeded for 10.13.100.240/255.255.255.248, next-hop FastEthernet0/0/10.12.100.254
*Mar 17 10:09:55.059: RT: updating ospf 10.13.100.240/29 (0x0):
via 10.12.100.254 Fa0/0 1048578

*Mar
RouterB# 17 10:09:55.063: BGP(0): lost route 10.13.100.240/29 for main IP table
*Mar 17 10:09:55.063: RT: closer admin distance for 10.13.100.240, flushing 1 routes
*Mar 17 10:09:55.063: RT: add 10.13.100.240/29 via 10.12.100.254, ospf metric [110/11]
*Mar 17 10:09:55.067: OSPF-1 EXTER: Process partial nssa spf queue
*Mar 17 10:09:55.071: BGP(0): Revise route installing 1 of 1 routes for 10.13.100.240/29 -> 10.12.100.254(global) to main IP table
*Mar 17 10:09:55.075: RT: updating bgp 10.13.100.240/29 (0x0):
via 10.12.100.254 1048577

*Mar 17 10:09:55.079: RT: rib update return code: 17
*Mar 17 10:09:55.083: BGP(0): route 10.13.100.240/29 up
*Mar 17 10:09:55.091: OSPF-1 SPF : Schedule partial SPF type 5, LSID 10.13.100.248, adv_rtr 192.168.254.2 area dummy area
*Mar 17 10:09:55.091: OSPF-1 SPF : Schedule partial SPF type 5, LSID 10.13.101.0, adv_rtr 192.168.254.2 area dummy area
*Mar 17 10:09:55.091: OSPF-1 SPF : Schedule partial SPF type 5, LSID 10.13.126.1, adv_rtr 192
RouterB#.168.254.2 area dummy area
*Mar 17 10:09:55.091: OSPF-1 SPF : Service partial SPF, spf instance 2115, 0/3/0
*Mar 17 10:09:55.091: OSPF-1 INTER: Process partial summary spf queue
*Mar 17 10:09:55.091: OSPF-1 EXTER: Process partial external spf queue
*Mar 17 10:09:55.091: OSPF-1 EXTER: Process partial spfQ: type 5, LSID 10.13.100.248, mask 255.255.255.248, adv_rtr 192.168.254.2, age 1, seq 0x800003B2, area dummy area
*Mar 17 10:09:55.091: OSPF-1 EXTER: Start partial processing Type 5 External LSA 10.13.100.248, mask 255.255.255.248
*Mar 17 10:09:55.091: OSPF-1 EXTER: adv_rtr 192.168.254.2, age 1, seq 0x800003B2, metric 10, metric-type 1, fw-addr 0.0.0.0
*Mar 17 10:09:55.091: OSPF-1 SPF : Add better path to LSA ID 10.13.100.248, gateway 10.12.100.254, dist 11
*Mar 17 10:09:55.091: OSPF-1 SPF : Add path: next-hop 10.12.100.254, interface FastEthernet0/0
*Mar 17 10:09:55.091: OSPF-1 EXTER: Route update succeeded for 10.13.100.248/255.255.255.248, next-hop FastEtherne
RouterB#t0/0/10.12.100.254
*Mar 17 10:09:55.091: RT: updating ospf 10.13.100.248/29 (0x0):
via 10.12.100.254 Fa0/0 1048578

*Mar 17 10:09:55.091: BGP(0): lost route 10.13.100.248/29 for main IP table
*Mar 17 10:09:55.091: RT: closer admin distance for 10.13.100.248, flushing 1 routes
*Mar 17 10:09:55.091: RT: add 10.13.100.248/29 via 10.12.100.254, ospf metric [110/11]
*Mar 17 10:09:55.091: OSPF-1 EXTER: Process partial spfQ: type 5, LSID 10.13.101.0, mask 255.255.255.252, adv_rtr 192.168.254.2, age 1, seq 0x800003B2, area dummy area
*Mar 17 10:09:55.095: OSPF-1 EXTER: Start partial processing Type 5 External LSA 10.13.101.0, mask 255.255.255.252
*Mar 17 10:09:55.095: OSPF-1 EXTER: adv_rtr 192.168.254.2, age 1, seq 0x800003B2, metric 10, metric-type 1, fw-addr 0.0.0.0
*Mar 17 10:09:55.095: OSPF-1 SPF : Add better path to LSA ID 10.13.101.0, gateway 10.12.100.254, dist 11
*Mar 17 10:09:55.095: OSPF-1 SPF : Add path: next-hop 10.12.100.254, interface FastEthernet0/0
RouterB#
*Mar 17 10:09:55.095: OSPF-1 EXTER: Route update succeeded for 10.13.101.0/255.255.255.252, next-hop FastEthernet0/0/10.12.100.254
*Mar 17 10:09:55.095: RT: updating ospf 10.13.101.0/30 (0x0):
via 10.12.100.254 Fa0/0 1048578

*Mar 17 10:09:55.095: BGP(0): lost route 10.13.101.0/30 for main IP table
*Mar 17 10:09:55.095: RT: closer admin distance for 10.13.101.0, flushing 1 routes
*Mar 17 10:09:55.095: RT: add 10.13.101.0/30 via 10.12.100.254, ospf metric [110/11]
*Mar 17 10:09:55.095: OSPF-1 EXTER: Process partial spfQ: type 5, LSID 10.13.126.1, mask 255.255.255.255, adv_rtr 192.168.254.2, age 1, seq 0x800003B2, area dummy area
*Mar 17 10:09:55.095: OSPF-1 EXTER: Start partial processing Type 5 External LSA 10.13.126.1, mask 255.255.255.255
*Mar 17 10:09:55.095: OSPF-1 EXTER: adv_rtr 192.168.254.2, age 1, seq 0x800003B2, metric 10, metric-type 1, fw-addr 0.0.0.0
*Mar 17 10:09:55.095: OSPF-1 SPF : Add better path to LSA ID 10.13.126.1, gateway 10.12.100.254, di
RouterB#st 11
*Mar 17 10:09:55.095: OSPF-1 SPF : Add path: next-hop 10.12.100.254, interface FastEthernet0/0
*Mar 17 10:09:55.095: OSPF-1 EXTER: Route update succeeded for 10.13.126.1/255.255.255.255, next-hop FastEthernet0/0/10.12.100.254
*Mar 17 10:09:55.095: RT: updating ospf 10.13.126.1/32 (0x0):
via 10.12.100.254 Fa0/0 1048578

*Mar 17 10:09:55.095: BGP(0): lost route 10.13.126.1/32 for main IP table
*Mar 17 10:09:55.095: RT: closer admin distance for 10.13.126.1, flushing 1 routes
*Mar 17 10:09:55.095: RT: add 10.13.126.1/32 via 10.12.100.254, ospf metric [110/11]
*Mar 17 10:09:55.095: OSPF-1 EXTER: Process partial nssa spf queue
*Mar 17 10:09:55.095: BGP: topo global:IPv4 Unicast:base Remove_fwdroute for 10.13.100.240/29
*Mar 17 10:09:55.095: BGP(0): Revise route installing 1 of 1 routes for 10.13.100.248/29 -> 10.12.100.254(global) to main IP table
*Mar 17 10:09:55.095: RT: updating bgp 10.13.100.248/29 (0x0):
via 10.12.100.254 1048577

*Mar 17 10:09:55
RouterB#.095: RT: rib update return code: 17
*Mar 17 10:09:55.095: BGP(0): Revise route installing 1 of 1 routes for 10.13.101.0/30 -> 10.12.100.254(global) to main IP table
*Mar 17 10:09:55.095: RT: updating bgp 10.13.101.0/30 (0x0):
via 10.12.100.254 1048577

*Mar 17 10:09:55.095: RT: rib update return code: 17
*Mar 17 10:09:55.095: BGP(0): Revise route installing 1 of 1 routes for 10.13.126.1/32 -> 10.12.100.254(global) to main IP table
*Mar 17 10:09:55.095: RT: updating bgp 10.13.126.1/32 (0x0):
via 10.12.100.254 1048577

*Mar 17 10:09:55.095: RT: rib update return code: 17
*Mar 17 10:09:55.099: BGP(0): 10.12.100.254 NEXT_HOP is set to self for net 10.13.100.240/29,
*Mar 17 10:09:55.103: BGP(0): (base) 10.12.100.254 send UPDATE (format) 10.13.100.240/29, next 10.12.100.249, metric 10, path Local
*Mar 17 10:09:55.107: BGP(0): route 10.13.100.248/29 up
*Mar 17 10:09:55.107: BGP(0): route 10.13.101.0/30 up
*Mar 17 10:09:55.107: BGP(0): route 10.13.126.1/32 up
*Ma
RouterB#r 17 10:09:55.107: BGP: topo global:IPv4 Unicast:base Remove_fwdroute for 10.13.100.248/29
*Mar 17 10:09:55.107: BGP: topo global:IPv4 Unicast:base Remove_fwdroute for 10.13.101.0/30
*Mar 17 10:09:55.107: BGP: topo global:IPv4 Unicast:base Remove_fwdroute for 10.13.126.1/32
*Mar 17 10:09:55.111: BGP(0): 10.12.100.254 NEXT_HOP is set to self for net 10.13.100.248/29,
*Mar 17 10:09:55.111: BGP(0): (base) 10.12.100.254 send UPDATE (format) 10.13.100.248/29, next 10.12.100.249, metric 10, path Local
*Mar 17 10:09:55.111: BGP(0): 10.12.100.254 NEXT_HOP is set to self for net 10.13.101.0/30,
*Mar 17 10:09:55.111: BGP(0): 10.12.100.254 NEXT_HOP is set to self for net 10.13.126.1/32,
*Mar 17 10:09:55.139: BGP(0): 10.12.100.254 rcv UPDATE about 10.13.100.240/29 -- withdrawn
*Mar 17 10:09:55.139: BGP(0): 10.12.100.254 rcv UPDATE about 10.13.100.248/29 -- withdrawn
*Mar 17 10:09:55.139: BGP(0): 10.12.100.254 rcv UPDATE about 10.13.101.0/30 -- withdrawn
*Mar 17 10:09:55.139: BGP(0):
RouterB#10.12.100.254 rcv UPDATE about 10.13.126.1/32 -- withdrawn
*Mar 17 10:10:00.051: OSPF-1 SPF : Detect MAXAGE in LSA type 5, LS ID 10.13.100.240, from 192.168.254.2
*Mar 17 10:10:00.051: OSPF-1 SPF : Detect generic change in LSA type 5, LSID 10.13.100.240, from 192.168.254.2 area 0
*Mar 17 10:10:00.055: OSPF-1 SPF : Schedule partial SPF type 5, LSID 10.13.100.240, adv_rtr 192.168.254.2 area dummy area
*Mar 17 10:10:00.055: OSPF-1 SPF : Service partial SPF, spf instance 2116, 0/1/0
*Mar 17 10:10:00.055: OSPF-1 INTER: Process partial summary spf queue
*Mar 17 10:10:00.055: OSPF-1 EXTER: Process partial external spf queue
*Mar 17 10:10:00.055: OSPF-1 EXTER: Process partial spfQ: type 5, LSID 10.13.100.240, mask 255.255.255.248, adv_rtr 192.168.254.2, age 3600, seq 0x800003B3, area dummy area
*Mar 17 10:10:00.055: OSPF-1 EXTER: Start partial processing Type 5 External LSA 10.13.100.240, mask 255.255.255.248
*Mar 17 10:10:00.055: OSPF-1 EXTER: adv_rtr 192.168.254.2, age 3600,
RouterB# seq 0x800003B3, metric 16777215, metric-type 1, fw-addr 10.12.100.249
*Mar 17 10:10:00.055: RT: del 10.13.100.240 via 10.12.100.254, ospf metric [110/11]
*Mar 17 10:10:00.059: RT: delete subnet route to 10.13.100.240/29
*Mar 17 10:10:00.059: OSPF-1 EXTER: Deleted external route 10.13.100.240/255.255.255.248
*Mar 17 10:10:00.059: OSPF-1 EXTER: Process partial nssa spf queue
*Mar 17 10:10:00.059: BGP(0): route 10.13.100.240/29 down
*Mar 17 10:10:00.063: BGP(0): no valid path for 10.13.100.240/29
*Mar 17 10:10:00.063: BGP: topo global:IPv4 Unicast:base Remove_fwdroute for 10.13.100.240/29
*Mar 17 10:10:00.063: BGP(0): (base) 10.12.100.254 send unreachable (format) 10.13.100.240/29
*Mar 17 10:10:00.083: BGP(0): 10.12.100.254 rcvd UPDATE w/ attr: nexthop 10.12.100.254, origin ?, localpref 100, metric 10, merged path 65222 65222 65222 65222, AS_PATH
*Mar 17 10:10:00.091: BGP(0): 10.12.100.254 rcvd 10.13.100.240/29
*Mar 17 10:10:00.091: BGP(0): Revise route installing 1 of 1 r
RouterB#outes for 10.13.100.240/29 -> 10.12.100.254(global) to main IP table
*Mar 17 10:10:00.091: RT: updating bgp 10.13.100.240/29 (0x0):
via 10.12.100.254 1048577

*Mar 17 10:10:00.091: RT: add 10.13.100.240/29 via 10.12.100.254, bgp metric [200/10]
*Mar 17 10:10:00.095: OSPF-1 SPF : Detect MAXAGE in LSA type 5, LS ID 10.13.100.248, from 192.168.254.2
*Mar 17 10:10:00.095: OSPF-1 SPF : Detect generic change in LSA type 5, LSID 10.13.100.248, from 192.168.254.2 area 0
*Mar 17 10:10:00.095: OSPF-1 SPF : Schedule partial SPF type 5, LSID 10.13.100.248, adv_rtr 192.168.254.2 area dummy area
*Mar 17 10:10:00.095: OSPF-1 SPF : Detect MAXAGE in LSA type 5, LS ID 10.13.101.0, from 192.168.254.2
*Mar 17 10:10:00.095: OSPF-1 SPF : Detect generic change in LSA type 5, LSID 10.13.101.0, from 192.168.254.2 area 0
*Mar 17 10:10:00.095: OSPF-1 SPF : Schedule partial SPF type 5, LSID 10.13.101.0, adv_rtr 192.168.254.2 area dummy area
*Mar 17 10:10:00.099: OSPF-1 SPF : Detect MAXA
RouterB#GE in LSA type 5, LS ID 10.13.126.1, from 192.168.254.2
*Mar 17 10:10:00.099: OSPF-1 SPF : Detect generic change in LSA type 5, LSID 10.13.126.1, from 192.168.254.2 area 0
*Mar 17 10:10:00.099: OSPF-1 SPF : Schedule partial SPF type 5, LSID 10.13.126.1, adv_rtr 192.168.254.2 area dummy area
*Mar 17 10:10:00.099: OSPF-1 SPF : Service partial SPF, spf instance 2117, 0/3/0
*Mar 17 10:10:00.099: OSPF-1 INTER: Process partial summary spf queue
*Mar 17 10:10:00.099: OSPF-1 EXTER: Process partial external spf queue
*Mar 17 10:10:00.099: OSPF-1 EXTER: Process partial spfQ: type 5, LSID 10.13.100.248, mask 255.255.255.248, adv_rtr 192.168.254.2, age 3600, seq 0x800003B3, area dummy area
*Mar 17 10:10:00.099: OSPF-1 EXTER: Start partial processing Type 5 External LSA 10.13.100.248, mask 255.255.255.248
*Mar 17 10:10:00.099: OSPF-1 EXTER: adv_rtr 192.168.254.2, age 3600, seq 0x800003B3, metric 16777215, metric-type 1, fw-addr 10.12.100.249
*Mar 17 10:10:00.099: RT: del 10.13.100.
RouterB#248 via 10.12.100.254, ospf metric [110/11]
*Mar 17 10:10:00.099: RT: delete subnet route to 10.13.100.248/29
*Mar 17 10:10:00.099: OSPF-1 EXTER: Deleted external route 10.13.100.248/255.255.255.248
*Mar 17 10:10:00.099: OSPF-1 EXTER: Process partial spfQ: type 5, LSID 10.13.101.0, mask 255.255.255.252, adv_rtr 192.168.254.2, age 3600, seq 0x800003B3, area dummy area
*Mar 17 10:10:00.099: OSPF-1 EXTER: Start partial processing Type 5 External LSA 10.13.101.0, mask 255.255.255.252
*Mar 17 10:10:00.099: OSPF-1 EXTER: adv_rtr 192.168.254.2, age 3600, seq 0x800003B3, metric 16777215, metric-type 1, fw-addr 10.12.100.249
*Mar 17 10:10:00.099: RT: del 10.13.101.0 via 10.12.100.254, ospf metric [110/11]
*Mar 17 10:10:00.099: RT: delete subnet route to 10.13.101.0/30
*Mar 17 10:10:00.099: OSPF-1 EXTER: Deleted external route 10.13.101.0/255.255.255.252
*Mar 17 10:10:00.099: OSPF-1 EXTER: Process partial spfQ: type 5, LSID 10.13.126.1, mask 255.255.255.255, adv_rtr 192.168.254.2,
RouterB# age 3600, seq 0x800003B3, area dummy area
*Mar 17 10:10:00.099: OSPF-1 EXTER: Start partial processing Type 5 External LSA 10.13.126.1, mask 255.255.255.255
*Mar 17 10:10:00.099: OSPF-1 EXTER: adv_rtr 192.168.254.2, age 3600, seq 0x800003B3, metric 16777215, metric-type 1, fw-addr 10.12.100.249
*Mar 17 10:10:00.099: RT: del 10.13.126.1 via 10.12.100.254, ospf metric [110/11]
*Mar 17 10:10:00.099: RT: delete subnet route to 10.13.126.1/32
*Mar 17 10:10:00.099: OSPF-1 EXTER: Deleted external route 10.13.126.1/255.255.255.255
*Mar 17 10:10:00.099: OSPF-1 EXTER: Process partial nssa spf queue
*Mar 17 10:10:00.099: BGP(0): route 10.13.100.248/29 down
*Mar 17 10:10:00.099: BGP(0): no valid path for 10.13.100.248/29
*Mar 17 10:10:00.099: BGP(0): route 10.13.101.0/30 down
*Mar 17 10:10:00.099: BGP(0): no valid path for 10.13.101.0/30
*Mar 17 10:10:00.099: BGP(0): route 10.13.126.1/32 down
*Mar 17 10:10:00.099: BGP(0): no valid path for 10.13.126.1/32
*Mar 17 10:10:00.099: BG
RouterB#P: topo global:IPv4 Unicast:base Remove_fwdroute for 10.13.100.248/29
*Mar 17 10:10:00.099: BGP: topo global:IPv4 Unicast:base Remove_fwdroute for 10.13.101.0/30
*Mar 17 10:10:00.099: BGP: topo global:IPv4 Unicast:base Remove_fwdroute for 10.13.126.1/32
*Mar 17 10:10:00.099: BGP(0): (base) 10.12.100.254 send unreachable (format) 10.13.100.248/29
*Mar 17 10:10:00.115: BGP(0): 10.12.100.254 rcvd UPDATE w/ attr: nexthop 10.12.100.254, origin ?, localpref 100, metric 0, merged path 65222 65222 65222 65222, AS_PATH
*Mar 17 10:10:00.119: BGP(0): 10.12.100.254 rcvd 10.13.100.248/29
*Mar 17 10:10:00.119: BGP(0): 10.12.100.254 rcvd 10.13.101.0/30
*Mar 17 10:10:00.119: BGP(0): 10.12.100.254 rcvd UPDATE w/ attr: nexthop 10.12.100.254, origin ?, localpref 100, metric 10, merged path 65222 65222 65222 65222, AS_PATH
*Mar 17 10:10:00.119: BGP(0): 10.12.100.254 rcvd 10.13.126.1/32
*Mar 17 10:10:00.119: BGP(0): Revise route installing 1 of 1 routes for 10.13.100.248/29 -> 10.12.100.254(glo
RouterB#bal) to main IP table
*Mar 17 10:10:00.119: RT: updating bgp 10.13.100.248/29 (0x0):
via 10.12.100.254 1048577

*Mar 17 10:10:00.119: RT: add 10.13.100.248/29 via 10.12.100.254, bgp metric [200/0]
*Mar 17 10:10:00.119: BGP(0): Revise route installing 1 of 1 routes for 10.13.101.0/30 -> 10.12.100.254(global) to main IP table
*Mar 17 10:10:00.119: RT: updating bgp 10.13.101.0/30 (0x0):
via 10.12.100.254 1048577

*Mar 17 10:10:00.119: RT: add 10.13.101.0/30 via 10.12.100.254, bgp metric [200/0]
*Mar 17 10:10:00.119: BGP(0): Revise route installing 1 of 1 routes for 10.13.126.1/32 -> 10.12.100.254(global) to main IP table
*Mar 17 10:10:00.119: RT: updating bgp 10.13.126.1/32 (0x0):
via 10.12.100.254 1048577

*Mar 17 10:10:00.119: RT: add 10.13.126.1/32 via 10.12.100.254, bgp metric [200/10]
*Mar 17 10:10:05.087: OSPF-1 SPF : Schedule partial SPF type 5, LSID 10.13.100.240, adv_rtr 192.168.254.2 area dummy area
*Mar 17 10:10:05.087: OSPF-1 SPF : Service
RouterB# partial SPF, spf instance 2118, 0/1/0
*Mar 17 10:10:05.087: OSPF-1 INTER: Process partial summary spf queue
*Mar 17 10:10:05.087: OSPF-1 EXTER: Process partial external spf queue
*Mar 17 10:10:05.087: OSPF-1 EXTER: Process partial spfQ: type 5, LSID 10.13.100.240, mask 255.255.255.248, adv_rtr 192.168.254.2, age 1, seq 0x800003B4, area dummy area
*Mar 17 10:10:05.087: OSPF-1 EXTER: Start partial processing Type 5 External LSA 10.13.100.240, mask 255.255.255.248
*Mar 17 10:10:05.087: OSPF-1 EXTER: adv_rtr 192.168.254.2, age 1, seq 0x800003B4, metric 10, metric-type 1, fw-addr 0.0.0.0
*Mar 17 10:10:05.087: OSPF-1 SPF : Add better path to LSA ID 10.13.100.240, gateway 10.12.100.254, dist 11
*Mar 17 10:10:05.087: OSPF-1 SPF : Add path: next-hop 10.12.100.254, interface FastEthernet0/0
*Mar 17 10:10:05.087: OSPF-1 EXTER: Route update succeeded for 10.13.100.240/255.255.255.248, next-hop FastEthernet0/0/10.12.100.254
*Mar 17 10:10:05.087: RT: updating ospf 10.13.100.2
RouterB#undebug all
All possible debugging has been turned off
RouterB#40/29 (0x0):
via 10.12.100.254 Fa0/0 1048578

*Mar 17 10:10:05.087: BGP(0): lost route 10.13.100.240/29 for main IP table
*Mar 17 10:10:05.087: RT: closer admin distance for 10.13.100.240, flushing 1 routes
*Mar 17 10:10:05.087: RT: add 10.13.100.240/29 via 10.12.100.254, ospf metric [110/11]
*Mar 17 10:10:05.087: OSPF-1 EXTER: Process partial nssa spf queue
*Mar 17 10:10:05.087: BGP(0): Revise route installing 1 of 1 routes for 10.13.100.240/29 -> 10.12.100.254(global) to main IP table
*Mar 17 10:10:05.087: RT: updating bgp 10.13.100.240/29 (0x0):
via 10.12.100.254 1048577

*Mar 17 10:10:05.091: RT: rib update return code: 17
*Mar 17 10:10:05.091: BGP(0): route 10.13.100.240/29 up
*Mar 17 10:10:05.091: BGP: topo global:IPv4 Unicast:base Remove_fwdroute for 10.13.100.240/29
*Mar 17 10:10:05.091: BGP(0): 10.12.100.254 NEXT_HOP is set to self for net 10.13.100.240/29,
*Mar 17 10:10:05.091: BGP(0): (base) 10.12.100.254 send UPDATE (format) 10.13.100.240/29, nex
RouterB#t 10.12.100.249, metric 10, path Local
*Mar 17 10:10:05.095: OSPF-1 SPF : Schedule partial SPF type 5, LSID 10.13.100.248, adv_rtr 192.168.254.2 area dummy area
*Mar 17 10:10:05.095: OSPF-1 SPF : Schedule partial SPF type 5, LSID 10.13.101.0, adv_rtr 192.168.254.2 area dummy area
*Mar 17 10:10:05.095: OSPF-1 SPF : Schedule partial SPF type 5, LSID 10.13.126.1, adv_rtr 192.168.254.2 area dummy area
*Mar 17 10:10:05.095: OSPF-1 SPF : Service partial SPF, spf instance 2119, 0/3/0
*Mar 17 10:10:05.095: OSPF-1 INTER: Process partial summary spf queue
*Mar 17 10:10:05.095: OSPF-1 EXTER: Process partial external spf queue
*Mar 17 10:10:05.095: OSPF-1 EXTER: Process partial spfQ: type 5, LSID 10.13.100.248, mask 255.255.255.248, adv_rtr 192.168.254.2, age 1, seq 0x800003B4, area dummy area
*Mar 17 10:10:05.095: OSPF-1 EXTER: Start partial processing Type 5 External LSA 10.13.100.248, mask 255.255.255.248
*Mar 17 10:10:05.095: OSPF-1 EXTER: adv_rtr 192.168.254.2, age 1, seq 0
RouterB#x800003B4, metric 10, metric-type 1, fw-addr 0.0.0.0
*Mar 17 10:10:05.095: OSPF-1 SPF : Add better path to LSA ID 10.13.100.248, gateway 10.12.100.254, dist 11
*Mar 17 10:10:05.095: OSPF-1 SPF : Add path: next-hop 10.12.100.254, interface FastEthernet0/0
*Mar 17 10:10:05.095: OSPF-1 EXTER: Route update succeeded for 10.13.100.248/255.255.255.248, next-hop FastEthernet0/0/10.12.100.254
*Mar 17 10:10:05.095: RT: updating ospf 10.13.100.248/29 (0x0):
via 10.12.100.254 Fa0/0 1048578

*Mar 17 10:10:05.099: BGP(0): lost route 10.13.100.248/29 for main IP table
*Mar 17 10:10:05.099: RT: closer admin distance for 10.13.100.248, flushing 1 routes
*Mar 17 10:10:05.099: RT: add 10.13.100.248/29 via 10.12.100.254, ospf metric [110/11]
*Mar 17 10:10:05.099: OSPF-1 EXTER: Process partial spfQ: type 5, LSID 10.13.101.0, mask 255.255.255.252, adv_rtr 192.168.254.2, age 1, seq 0x800003B4, area dummy area
*Mar 17 10:10:05.099: OSPF-1 EXTER: Start partial processing Type 5 Ex
RouterB#ternal LSA 10.13.101.0, mask 255.255.255.252
*Mar 17 10:10:05.099: OSPF-1 EXTER: adv_rtr 192.168.254.2, age 1, seq 0x800003B4, metric 10, metric-type 1, fw-addr 0.0.0.0
*Mar 17 10:10:05.099: OSPF-1 SPF : Add better path to LSA ID 10.13.101.0, gateway 10.12.100.254, dist 11
*Mar 17 10:10:05.099: OSPF-1 SPF : Add path: next-hop 10.12.100.254, interface FastEthernet0/0
*Mar 17 10:10:05.099: OSPF-1 EXTER: Route update succeeded for 10.13.101.0/255.255.255.252, next-hop FastEthernet0/0/10.12.100.254
*Mar 17 10:10:05.099: RT: updating ospf 10.13.101.0/30 (0x0):
via 10.12.100.254 Fa0/0 1048578

*Mar 17 10:10:05.099: BGP(0): lost route 10.13.101.0/30 for main IP table
*Mar 17 10:10:05.099: RT: closer admin distance for 10.13.101.0, flushing 1 routes
*Mar 17 10:10:05.099: RT: add 10.13.101.0/30 via 10.12.100.254, ospf metric [110/11]
*Mar 17 10:10:05.099: OSPF-1 EXTER: Process partial spfQ: type 5, LSID 10.13.126.1, mask 255.255.255.255, adv_rtr 192.168.254.2, age 1
RouterB#, seq 0x800003B4, area dummy area
*Mar 17 10:10:05.099: OSPF-1 EXTER: Start partial processing Type 5 External LSA 10.13.126.1, mask 255.255.255.255
*Mar 17 10:10:05.099: OSPF-1 EXTER: adv_rtr 192.168.254.2, age 1, seq 0x800003B4, metric 10, metric-type 1, fw-addr 0.0.0.0
*Mar 17 10:10:05.099: OSPF-1 SPF : Add better path to LSA ID 10.13.126.1, gateway 10.12.100.254, dist 11
*Mar 17 10:10:05.099: OSPF-1 SPF : Add path: next-hop 10.12.100.254, interface FastEthernet0/0
*Mar 17 10:10:05.099: OSPF-1 EXTER: Route update succeeded for 10.13.126.1/255.255.255.255, next-hop FastEthernet0/0/10.12.100.254
*Mar 17 10:10:05.099: RT: updating ospf 10.13.126.1/32 (0x0):
via 10.12.100.254 Fa0/0 1048578

*Mar 17 10:10:05.099: BGP(0): lost route 10.13.126.1/32 for main IP table
*Mar 17 10:10:05.099: RT: closer admin distance for 10.13.126.1, flushing 1 routes
*Mar 17 10:10:05.099: RT: add 10.13.126.1/32 via 10.12.100.254, ospf metric [110/11]
*Mar 17 10:10:05.099: OSPF-1
RouterB# EXTER: Process partial nssa spf queue
*Mar 17 10:10:05.099: BGP(0): route 10.13.100.248/29 up
*Mar 17 10:10:05.099: BGP(0): route 10.13.101.0/30 up
*Mar 17 10:10:05.099: BGP(0): route 10.13.126.1/32 up
*Mar 17 10:10:05.099: BGP: topo global:IPv4 Unicast:base Remove_fwdroute for 10.13.100.248/29
*Mar 17 10:10:05.103: BGP: topo global:IPv4 Unicast:base Remove_fwdroute for 10.13.101.0/30
*Mar 17 10:10:05.103: BGP: topo global:IPv4 Unicast:base Remove_fwdroute for 10.13.126.1/32
*Mar 17 10:10:05.103: BGP(0): 10.12.100.254 NEXT_HOP is set to self for net 10.13.100.248/29,
*Mar 17 10:10:05.103: BGP(0): (base) 10.12.100.254 send UPDATE (format) 10.13.100.248/29, next 10.12.100.249, metric 10, path Local
*Mar 17 10:10:05.103: BGP(0): 10.12.100.254 NEXT_HOP is set to self for net 10.13.101.0/30,
*Mar 17 10:10:05.103: BGP(0): 10.12.100.254 NEXT_HOP is set to self for net 10.13.126.1/32,
*Mar 17 10:10:05.107: BGP(0): 10.12.100.254 rcv UPDATE about 10.13.100.240/29 -- withdrawn
*M
RouterB#ar 17 10:10:05.115: BGP(0): 10.12.100.254 rcv UPDATE about 10.13.100.248/29 -- withdrawn
*Mar 17 10:10:05.115: BGP(0): 10.12.100.254 rcv UPDATE about 10.13.101.0/30 -- withdrawn
*Mar 17 10:10:05.115: BGP(0): 10.12.100.254 rcv UPDATE about 10.13.126.1/32 -- withdrawn
*Mar 17 10:10:10.079: OSPF-1 SPF : Detect MAXAGE in LSA type 5, LS ID 10.13.100.240, from 192.168.254.2
*Mar 17 10:10:10.079: OSPF-1 SPF : Detect generic change in LSA type 5, LSID 10.13.100.240, from 192.168.254.2 area 0
*Mar 17 10:10:10.079: OSPF-1 SPF : Schedule partial SPF type 5, LSID 10.13.100.240, adv_rtr 192.168.254.2 area dummy area
*Mar 17 10:10:10.079: OSPF-1 SPF : Service partial SPF, spf instance 2120, 0/1/0
*Mar 17 10:10:10.079: OSPF-1 INTER: Process partial summary spf queue
*Mar 17 10:10:10.079: OSPF-1 EXTER: Process partial external spf queue
*Mar 17 10:10:10.079: OSPF-1 EXTER: Process partial spfQ: type 5, LSID 10.13.100.240, mask 255.255.255.248, adv_rtr 192.168.254.2, age 3600, seq 0x80000
RouterB#3B5, area dummy area
*Mar 17 10:10:10.079: OSPF-1 EXTER: Start partial processing Type 5 External LSA 10.13.100.240, mask 255.255.255.248
*Mar 17 10:10:10.079: OSPF-1 EXTER: adv_rtr 192.168.254.2, age 3600, seq 0x800003B5, metric 16777215, metric-type 1, fw-addr 10.12.100.249
*Mar 17 10:10:10.079: RT: del 10.13.100.240 via 10.12.100.254, ospf metric [110/11]
*Mar 17 10:10:10.079: RT: delete subnet route to 10.13.100.240/29
*Mar 17 10:10:10.079: OSPF-1 EXTER: Deleted external route 10.13.100.240/255.255.255.248
*Mar 17 10:10:10.079: OSPF-1 EXTER: Process partial nssa spf queue
*Mar 17 10:10:10.079: BGP(0): route 10.13.100.240/29 down
*Mar 17 10:10:10.083: BGP(0): no valid path for 10.13.100.240/29
*Mar 17 10:10:10.083: BGP: topo global:IPv4 Unicast:base Remove_fwdroute for 10.13.100.240/29
*Mar 17 10:10:10.083: BGP(0): (base) 10.12.100.254 send unreachable (format) 10.13.100.240/29
*Mar 17 10:10:10.099: BGP(0): 10.12.100.254 rcvd UPDATE w/ attr: nexthop 10.12.100.254, or
RouterB#igin ?, localpref 100, metric 10, merged path 65222 65222 65222 65222, AS_PATH
*Mar 17 10:10:10.099: BGP(0): 10.12.100.254 rcvd 10.13.100.240/29
*Mar 17 10:10:10.099: BGP(0): Revise route installing 1 of 1 routes for 10.13.100.240/29 -> 10.12.100.254(global) to main IP table
*Mar 17 10:10:10.099: RT: updating bgp 10.13.100.240/29 (0x0):
via 10.12.100.254 1048577

*Mar 17 10:10:10.099: RT: add 10.13.100.240/29 via 10.12.100.254, bgp metric [200/10]
*Mar 17 10:10:10.111: OSPF-1 SPF : Detect MAXAGE in LSA type 5, LS ID 10.13.100.248, from 192.168.254.2
*Mar 17 10:10:10.111: OSPF-1 SPF : Detect generic change in LSA type 5, LSID 10.13.100.248, from 192.168.254.2 area 0
*Mar 17 10:10:10.111: OSPF-1 SPF : Schedule partial SPF type 5, LSID 10.13.100.248, adv_rtr 192.168.254.2 area dummy area
*Mar 17 10:10:10.111: OSPF-1 SPF : Detect MAXAGE in LSA type 5, LS ID 10.13.101.0, from 192.168.254.2
*Mar 17 10:10:10.111: OSPF-1 SPF : Detect generic change in LSA type 5, LSID
RouterB#10.13.101.0, from 192.168.254.2 area 0
*Mar 17 10:10:10.111: OSPF-1 SPF : Schedule partial SPF type 5, LSID 10.13.101.0, adv_rtr 192.168.254.2 area dummy area
*Mar 17 10:10:10.111: OSPF-1 SPF : Detect MAXAGE in LSA type 5, LS ID 10.13.126.1, from 192.168.254.2
*Mar 17 10:10:10.111: OSPF-1 SPF : Detect generic change in LSA type 5, LSID 10.13.126.1, from 192.168.254.2 area 0
*Mar 17 10:10:10.111: OSPF-1 SPF : Schedule partial SPF type 5, LSID 10.13.126.1, adv_rtr 192.168.254.2 area dummy area
*Mar 17 10:10:10.111: OSPF-1 SPF : Service partial SPF, spf instance 2121, 0/3/0
*Mar 17 10:10:10.111: OSPF-1 INTER: Process partial summary spf queue
*Mar 17 10:10:10.111: OSPF-1 EXTER: Process partial external spf queue
*Mar 17 10:10:10.111: OSPF-1 EXTER: Process partial spfQ: type 5, LSID 10.13.100.248, mask 255.255.255.248, adv_rtr 192.168.254.2, age 3600, seq 0x800003B5, area dummy area
*Mar 17 10:10:10.111: OSPF-1 EXTER: Start partial processing Type 5 External LSA 10.13.100
RouterB#.248, mask 255.255.255.248
*Mar 17 10:10:10.111: OSPF-1 EXTER: adv_rtr 192.168.254.2, age 3600, seq 0x800003B5, metric 16777215, metric-type 1, fw-addr 10.12.100.249
*Mar 17 10:10:10.111: RT: del 10.13.100.248 via 10.12.100.254, ospf metric [110/11]
*Mar 17 10:10:10.111: RT: delete subnet route to 10.13.100.248/29
*Mar 17 10:10:10.111: OSPF-1 EXTER: Deleted external route 10.13.100.248/255.255.255.248
*Mar 17 10:10:10.111: OSPF-1 EXTER: Process partial spfQ: type 5, LSID 10.13.101.0, mask 255.255.255.252, adv_rtr 192.168.254.2, age 3600, seq 0x800003B5, area dummy area
*Mar 17 10:10:10.111: OSPF-1 EXTER: Start partial processing Type 5 External LSA 10.13.101.0, mask 255.255.255.252
*Mar 17 10:10:10.111: OSPF-1 EXTER: adv_rtr 192.168.254.2, age 3600, seq 0x800003B5, metric 16777215, metric-type 1, fw-addr 10.12.100.249
*Mar 17 10:10:10.111: RT: del 10.13.101.0 via 10.12.100.254, ospf metric [110/11]
*Mar 17 10:10:10.115: RT: delete subnet route to 10.13.101.0/30
*Mar 17
RouterB# 10:10:10.115: OSPF-1 EXTER: Deleted external route 10.13.101.0/255.255.255.252
*Mar 17 10:10:10.115: OSPF-1 EXTER: Process partial spfQ: type 5, LSID 10.13.126.1, mask 255.255.255.255, adv_rtr 192.168.254.2, age 3600, seq 0x800003B5, area dummy area
*Mar 17 10:10:10.115: OSPF-1 EXTER: Start partial processing Type 5 External LSA 10.13.126.1, mask 255.255.255.255
*Mar 17 10:10:10.115: OSPF-1 EXTER: adv_rtr 192.168.254.2, age 3600, seq 0x800003B5, metric 16777215, metric-type 1, fw-addr 10.12.100.249
*Mar 17 10:10:10.115: RT: del 10.13.126.1 via 10.12.100.254, ospf metric [110/11]
*Mar 17 10:10:10.115: RT: delete subnet route to 10.13.126.1/32
*Mar 17 10:10:10.115: OSPF-1 EXTER: Deleted external route 10.13.126.1/255.255.255.255
*Mar 17 10:10:10.115: OSPF-1 EXTER: Process partial nssa spf queue
*Mar 17 10:10:10.115: BGP(0): route 10.13.100.248/29 down
*Mar 17 10:10:10.115: BGP(0): no valid path for 10.13.100.248/29
RouterB#10:10:10.115: BGP(0): route 10.13.101.0/30 down
*Mar 17 10:10:10.115: BGP(0): no valid path for 10.13.101.0/30
*Mar 17 10:10:10.115: BGP(0): route 10.13.126.1/32 down
*Mar 17 10:10:10.115: BGP(0): no valid path for 10.13.126.1/32
*Mar 17 10:10:10.115: BGP: topo global:IPv4 Unicast:base Remove_fwdroute for 10.13.100.248/29
*Mar 17 10:10:10.119: BGP: topo global:IPv4 Unicast:base Remove_fwdroute for 10.13.101.0/30
*Mar 17 10:10:10.119: BGP: topo global:IPv4 Unicast:base Remove_fwdroute for 10.13.126.1/32
*Mar 17 10:10:10.119: BGP(0): (base) 10.12.100.254 send unreachable (format) 10.13.100.248/29
*Mar 17 10:10:10.139: BGP(0): 10.12.100.254 rcvd UPDATE w/ attr: nexthop 10.12.100.254, origin ?, localpref 100, metric 0, merged path 65222 65222 65222 65222, AS_PATH
*Mar 17 10:10:10.143: BGP(0): 10.12.100.254 rcvd 10.13.100.248/29
*Mar 17 10:10:10.143: BGP(0): 10.12.100.254 rcvd 10.13.101.0/30
*Mar 17 10:10:10.143: BGP(0): 10.12.100.254 rcvd UPDATE w/ attr: nexthop 10.12.100.254, origin ?, localpref 100, metric 10, merged pat
RouterB#h 65222 65222 65222 65222, AS_PATH
*Mar 17 10:10:10.143: BGP(0): 10.12.100.254 rcvd 10.13.126.1/32
*Mar 17 10:10:10.143: BGP(0): Revise route installing 1 of 1 routes for 10.13.100.248/29 -> 10.12.100.254(global) to main IP table
*Mar 17 10:10:10.143: RT: updating bgp 10.13.100.248/29 (0x0):
via 10.12.100.254 1048577

*Mar 17 10:10:10.143: RT: add 10.13.100.248/29 via 10.12.100.254, bgp metric [200/0]
*Mar 17 10:10:10.143: BGP(0): Revise route installing 1 of 1 routes for 10.13.101.0/30 -> 10.12.100.254(global) to main IP table
*Mar 17 10:10:10.143: RT: updating bgp 10.13.101.0/30 (0x0):
via 10.12.100.254 1048577

*Mar 17 10:10:10.143: RT: add 10.13.101.0/30 via 10.12.100.254, bgp metric [200/0]
*Mar 17 10:10:10.143: BGP(0): Revise route installing 1 of 1 routes for 10.13.126.1/32 -> 10.12.100.254(global) to main IP table
*Mar 17 10:10:10.147: RT: updating bgp 10.13.126.1/32 (0x0):
via 10.12.100.254 1048577

*Mar 17 10:10:10.147: RT: add 10.13.126.1/
RouterB#32 via 10.12.100.254, bgp metric [200/10]
*Mar 17 10:10:12.519: BGP(0): (base) 192.168.100.2 send UPDATE (format) 10.13.100.240/29, next 192.168.100.1, metric 10, path 65222 65222 65222 65222
*Mar 17 10:10:12.523: BGP(0): (base) 192.168.100.2 send UPDATE (format) 10.13.100.248/29, next 192.168.100.1, metric 0, path 65222 65222 65222 65222
*Mar 17 10:10:12.527: BGP(0): (base) 192.168.100.2 send UPDATE (format) 10.13.126.1/32, next 192.168.100.1, metric 10, path 65222 65222 65222 65222
*Mar 17 10:10:15.079: OSPF-1 SPF : Schedule partial SPF type 5, LSID 10.13.100.240, adv_rtr 192.168.254.2 area dummy area
*Mar 17 10:10:15.083: OSPF-1 SPF : Service partial SPF, spf instance 2122, 0/1/0
*Mar 17 10:10:15.083: OSPF-1 INTER: Process partial summary spf queue
*Mar 17 10:10:15.083: OSPF-1 EXTER: Process partial external spf queue
*Mar 17 10:10:15.083: OSPF-1 EXTER: Process partial spfQ: type 5, LSID 10.13.100.240, mask 255.255.255.248, adv_rtr 192.168.254.2, age 1, seq 0x800003B6, a
RouterB#rea dummy area
*Mar 17 10:10:15.083: OSPF-1 EXTER: Start partial processing Type 5 External LSA 10.13.100.240, mask 255.255.255.248
*Mar 17 10:10:15.083: OSPF-1 EXTER: adv_rtr 192.168.254.2, age 1, seq 0x800003B6, metric 10, metric-type 1, fw-addr 0.0.0.0
*Mar 17 10:10:15.083: OSPF-1 SPF : Add better path to LSA ID 10.13.100.240, gateway 10.12.100.254, dist 11
*Mar 17 10:10:15.083: OSPF-1 SPF : Add path: next-hop 10.12.100.254, interface FastEthernet0/0
*Mar 17 10:10:15.083: OSPF-1 EXTER: Route update succeeded for 10.13.100.240/255.255.255.248, next-hop FastEthernet0/0/10.12.100.254
*Mar 17 10:10:15.083: RT: updating ospf 10.13.100.240/29 (0x0):
via 10.12.100.254 Fa0/0 1048578

*Mar 17 10:10:15.083: BGP(0): lost route 10.13.100.240/29 for main IP table
*Mar 17 10:10:15.083: RT: closer admin distance for 10.13.100.240, flushing 1 routes
*Mar 17 10:10:15.083: RT: add 10.13.100.240/29 via 10.12.100.254, ospf metric [110/11]
*Mar 17 10:10:15.083: OSPF-1 EXTE
RouterB#R: Process partial nssa spf queue
*Mar 17 10:10:15.083: BGP(0): Revise route installing 1 of 1 routes for 10.13.100.240/29 -> 10.12.100.254(global) to main IP table
*Mar 17 10:10:15.083: RT: updating bgp 10.13.100.240/29 (0x0):
via 10.12.100.254 1048577

*Mar 17 10:10:15.087: RT: rib update return code: 17
*Mar 17 10:10:15.087: BGP(0): route 10.13.100.240/29 up
RouterB#

 

 

 

 

Hello

Looks like you have a loop due to mutual redistribution between bgp/ospf via your multiple exits points and routes are oscillating between bgp/ospf routing processes.


Could try add the following which will tas bgp routes into ospf but then ospf will deny these tag routes to be re-advertised back into bgp.


Rtrs A & b in both sites

route-map BGP-OSPF permit 10
set tag 500

route-map OSPF-BGP deny 10
match tag 500
route-map OSPF-BGP permit 99


Site A -
rtr a
router ospf 1
redistribute bgp 65111 metric 10 metric-type 2 subnets route-map BGP-OSPF
redistribute static metric 10 metric-type 2 subnets tag 500


router bgp 65111
redistribute ospf 1 metric 10 match internal external 1 external 2 route-map OSPF-BGP

rtr b
router ospf 1
redistribute static metric 10 metric-type 1 subnets route-map BGP-OSPF
redistribute static metric 10 metric-type 1 subnets tag 500

router bgp 65111
redistribute ospf 1 metric 10 match internal external 1 external 2 route-map OSPF-BGP



SITE B
rtra
router ospf 1
redistribute bgp 65222 metric 10 metric-type 2 subnets route-map BGP-OSPF
redistribute static metric 10 metric-type 2 subnets tag 500


router bgp 65222
redistribute ospf 1 metric 10 match internal external 1 external 2 route-map OSPF-BGP

 

rtrb
router ospf 1
redistribute bgp 65222 metric 10 metric-type 1 subnets route-map BGP-OSPF
redistribute static metric 10 metric-type 1 subnets tag 500

router bgp 65222
redistribute ospf 1 metric 10 match internal external 1 external 2 route-map OSPF-BGP

 


Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul

Hi Paul,

 

Thanks for your reply.

 

I have implemented your solution, however wanted to understand your method. My understanding is when you redistributing between BGP and OSPF BGP will always take over due to the lower AD and as a result avoid the loop.

 

I wanted to ask, should I be redistributing OSPF into BGP and BGP into OSPF in Router A and Router B on each site? This occurs on Router A on both sites but not on Router B on both sites?

 

 

Thanks.


@John Peterson wrote:

My understanding is when you redistributing between BGP and OSPF BGP will always take over due to the lower AD and as a result avoid the loop.

 



When you mutually redistribute with multiple exits points your open yourself up to route-feedback.

 

For example , RtrA:siteA has received a route in ospf originated from bgp via redistribution before Rtrb:siteA has, So this route is now seen by site A rtr's C/B as an ospf route, RtrB:siteA now redistributes the same route that originated in bgp back into bgp


Now due to timers etc.. you could see a route churn between ospf and bgp for the same prefix whilst they update their own ribs tables thus this same prefix could be seen in ospf then bgp then ospf again...Hence a loop could establish between two rtrs using each other to reach the same prefix.

 

 


@John Peterson wrote:

I wanted to ask, should I be redistributing OSPF into BGP and BGP into OSPF in Router A and Router B on each site? This occurs on Router A on both sites but not on Router B on both sites?


It could have occurred on the B rtrs, its all down to which rtr was able to begin it redistribution first.
I would say mutual redistribution with multiple exits points is okay and necessary in most cases but you need to prevent against sub-optimal routing and loops.

By the way did the route-map tagging help your issue?


Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul

Hi Paul,

Thanks and yes the solution of using route tags did work. Thank you.

I wanted to ask in Site A, Router B, we have a network which is connected via static, should this static route be redistributed into OSPF and BGP or only OSPF? - In addition, when I redistribute this route should it be tagged to stop route-feedback?

 

When we have connected networks to Router B in Site A, should these network be advertised into BGP and OSPF?


Thanks.

Hello


@spscisco wrote:

Hi Paul,

Thanks and yes the solution of using route tags did work. Thank you.

I wanted to ask in Site A, Router B, we have a network which is connected via static, should this static route be redistributed into OSPF and BGP or only OSPF? - In addition, when I redistribute this route should it be tagged to stop route-feedback?


I think had already included your statics with the same tag of 500 I assumed you required reachability, 

FYI -Redistributing statics into ospf  would advertise them into bgp also due to the mutual redistribution 

 

 


When we have connected networks to Router B in Site A, should these network be advertised into BGP and OSPF?


If you need them to reachable or they are being used for reachability  i would say yes.


Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul


@paul driver wrote:

Hello


@spscisco wrote:

Hi Paul,

Thanks and yes the solution of using route tags did work. Thank you.

I wanted to ask in Site A, Router B, we have a network which is connected via static, should this static route be redistributed into OSPF and BGP or only OSPF? - In addition, when I redistribute this route should it be tagged to stop route-feedback?


I think had already included your statics with the same tag of 500 I assumed you required reachability, 

FYI -Redistributing statics into ospf  would advertise them into bgp also due to the mutual redistribution 


Thank you Paul, therefore as long as the routes are tagged when redistributed from static we would avoid the mutual redistribution problem?

 

We also have connected interfaces (SVI) which we need to be reachable via OSPF and BGP, I would normally advertise these networks via the 'network' command under each routing protocol, however, I have noticed, I then face the same problem where the connected route begins to flap (route feedback), without the route-maps.

When the route maps are added to the routing protocols (appended to the redistribute command) and the connected network are advertised using the 'network' inside for OSPF and BGP the route feedback stops. - I'm trying to understand why when the network is advertised via the 'network' command we do not notice route feedback on the advertised (connected) routes, but when we redistribute from another network routing protocol we notice route feedback, without the route-maps, it as if the networks advertised via the network automatically have the tags added.

 

Which is the recommended method to advertise these network, via the 'network' command or redistribution as connected interfaces with the route-map to tags routes, instead of using the network command?

 

Much appreciated. 

 

Hello

 


@spscisco wrote:

Thank you Paul, therefore as long as the routes are tagged when redistributed from Static we would avoid the mutual redistribution problem?

You already performing mutual redistribution so what i mean is when you redistribute your statics into OSPF then they will be ospf rib table thus will the be advertised in to bpp due to the mutual redistribution 

 

 


We also have connected interfaces (SVI) which we need to be reachable via OSPF and BGP, I would normally advertise these networks via the 'network' command under each routing protocol, however, I have noticed, I then face the same problem where the connected route begin to flap (route feedback). - Should these be redistributed as connected interfaces with the route-map to tags routes, instead of using the network command?


Again connected interfaces would suggest use the network command then these will the be advertised in to bpp due to the mutual redistribution.


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Kind Regards
Paul
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