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BGP ROUTE INJECTED IN GLOBAL TABLE BUT REMOTE ROUTE UNREACHABLE

Isaac001
Level 1
Level 1

Dear Community,

I have I lab setup as attached where R10-R3-R4-R5-R6-R11

BGP routes for R6 routes appear in the routing table of R3 and vice-versa. R5 does the route redistribution between BGP 65200 and EIGRP 100 and vice versa. However, when I try to ping the route at R6 from R3 I can't reach that destination the reverse is also true,why?

================show ip route of R3=====================

R3#show ip route | b Gat
Gateway of last resort is not set

10.0.0.0/8 is variably subnetted, 5 subnets, 3 masks
C 10.12.1.0/24 is directly connected, GigabitEthernet0/0
L 10.12.1.1/32 is directly connected, GigabitEthernet0/0
S 10.13.1.0/24 [1/0] via 10.12.1.2
S 10.14.1.0/24 [1/0] via 10.12.1.2
B 10.14.1.0/30 [200/0] via 10.13.1.2, 01:05:46
192.168.3.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.3.0/24 is directly connected, GigabitEthernet0/1
L 192.168.3.3/32 is directly connected, GigabitEthernet0/1
B 192.168.6.0/24 [200/3072] via 10.14.1.2, 00:55:38
R3#

================show ip route of R6=====================

R6#show ip route | b Gat
Gateway of last resort is not set

10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C 10.14.1.0/30 is directly connected, GigabitEthernet0/2
L 10.14.1.2/32 is directly connected, GigabitEthernet0/2
D EX 192.168.3.0/24
[170/25600512] via 10.14.1.1, 00:58:29, GigabitEthernet0/2
192.168.6.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.6.0/24 is directly connected, GigabitEthernet0/0
L 192.168.6.6/32 is directly connected, GigabitEthernet0/0
R6#

I read somewhere that "BGP routers do not
have to be in the data plane (path) to exchange prefixes, but all routers in the data path need
to know all the routes that will be forwarded through them."

So I expected this lab to work but something is wrong, kingly review experts!

Regards,

Isaac.

1 Accepted Solution

Accepted Solutions

I found issue friend check below 
typo GRE not GRP

topology.png

View solution in original post

28 Replies 28

can I see the topology 

MHM

Hi @MHM Cisco World ,

Thanks for reviewing, kindly see attached.

one more ask please can you show me between which router you run eigrp and between which you run bgp 
thanks  

MHM

Sure @HMHMHM  EIGRP 100 running between R5 and R6, iBGP 65200 between R3 and R5, the other routers don't have any routing enabled.

in R3 and R5 use 
neighbor x.x.x.x next-hop-self 
then try ping 

MHM

configured as below

======R3=======

R3(config-router)#do sh run | s bgp
router bgp 65200
bgp log-neighbor-changes
network 192.168.3.0
neighbor 10.13.1.2 remote-as 65200
neighbor 10.13.1.2 next-hop-self

===========R5=============

router bgp 65200
bgp log-neighbor-changes
no bgp default ipv4-unicast
neighbor 10.12.1.1 remote-as 65200
!
address-family ipv4
bgp redistribute-internal
redistribute eigrp 100
neighbor 10.12.1.1 activate
neighbor 10.12.1.1 next-hop-self
exit-address-family
R5(config-router-af)#

======TRACEFROM R3===

R3(config-router)#do traceroute 192.168.6.6
Type escape sequence to abort.
Tracing the route to 192.168.6.6
VRF info: (vrf in name/id, vrf out name/id)
1 10.12.1.2 7 msec 14 msec 3 msec
2 10.12.1.2 !H !H *

still cant reach 192.168.6.6 from R3

 

check below
MHM

I found issue friend check below 
typo GRE not GRP

topology.png

Kindly see below configurations for GRE on R3 and R5. Am using 192.168.1.0/30 as Tunnel 100 subnet and advertising via bgp as shown below, still have reachability issue

=============R3===========

R3(config-router)#do sh run | s Tunnel
interface Tunnel100
ip address 192.168.100.1 255.255.255.252
tunnel source GigabitEthernet0/1
tunnel destination 10.13.1.2
R3(config-router)#do sh run | s bgp
router bgp 65200
bgp log-neighbor-changes
network 192.168.1.0 mask 255.255.255.252
network 192.168.3.0
neighbor 10.13.1.2 remote-as 65200
neighbor 10.13.1.2 next-hop-self
R3(config-router)#

=======R5============

R5(config-router-af)#do sh run | s Tunnel
interface Tunnel100
ip address 192.168.1.2 255.255.255.252
tunnel source GigabitEthernet0/1
tunnel destination 10.12.1.1
R5(config-router-af)#do sh run | s bgp
redistribute bgp 65200 metric 100 1 255 1 1500
router bgp 65200
bgp log-neighbor-changes
no bgp default ipv4-unicast
neighbor 10.12.1.1 remote-as 65200
!
address-family ipv4
bgp redistribute-internal
network 192.168.1.0 mask 255.255.255.252
redistribute eigrp 100
neighbor 10.12.1.1 activate
neighbor 10.12.1.1 next-hop-self
exit-address-family
R5(config-router-af)#

first do
show ip interface brief <<- check if the GRE tunnel is UP/UP 
then 
we use GRE tunnel IP as neighbor IP in BGP not advertise via BGP 
i.e. 

router bgp 65200
bgp log-neighbor-changes
no bgp default ipv4-unicast
neighbor 10.12.1.1 remote-as 65200 <<- remove this 
neighbor 192.168.1.1 remote-as 65200 <<- the GRE tunnel IP of Peer 

neighbor 192.168.1.1 next-hop-self 

do same except use .1 in other router 


MHM

 

bgp not forming but tunnel subnet appears in bgp table

=============R3============

R3(config-router)#do sh ip int brief | exc unass
Interface IP-Address OK? Method Status Protocol
GigabitEthernet0/0 10.12.1.1 YES NVRAM up up
GigabitEthernet0/1 192.168.3.3 YES NVRAM up up
Tunnel100 192.168.1.1 YES manual up up

R3(config-router)#do sh ip bgp | b N
RPKI validation codes: V valid, I invalid, N Not found

Network Next Hop Metric LocPrf Weight Path
*> 192.168.1.0/30 0.0.0.0 0 32768 i
*> 192.168.3.0 0.0.0.0 0 32768 i
R3(config-router)#do sh ip bgp summ | b N
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
192.168.1.2 4 65200 0 0 1 0 0 never Active
R3(config-router)#do sh run | s bgp
router bgp 65200
bgp log-neighbor-changes
network 192.168.1.0 mask 255.255.255.252
network 192.168.3.0
neighbor 192.168.1.2 remote-as 65200
neighbor 192.168.1.2 next-hop-self
neighbor 192.168.1.2 soft-reconfiguration inbound
R3(config-router)#

==============R5===================

R5(config)#do sh ip int brief | exc unass
Interface IP-Address OK? Method Status Protocol
GigabitEthernet0/1 10.13.1.2 YES NVRAM up up
GigabitEthernet0/2 10.14.1.1 YES NVRAM up up
Loopback0 192.168.5.1 YES NVRAM up up
Tunnel100 192.168.1.2 YES NVRAM up up

R5(config)#do sh ip bgp | b N
RPKI validation codes: V valid, I invalid, N Not found

Network Next Hop Metric LocPrf Weight Path
*> 10.14.1.0/30 0.0.0.0 0 32768 ?
*> 192.168.1.0/30 0.0.0.0 0 32768 i
*> 192.168.6.0 10.14.1.2 3072 32768 ?
R5(config)#do sh ip bgp summ | N
^
% Invalid input detected at '^' marker.

R5(config)#do sh ip bgp summ | b N
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
192.168.1.1 4 65200 0 0 1 0 0 never Active

R5(config)#do sh run | s bgp
redistribute bgp 65200 metric 100 1 255 1 1500
router bgp 65200
bgp log-neighbor-changes
no bgp default ipv4-unicast
neighbor 192.168.1.1 remote-as 65200
!
address-family ipv4
bgp redistribute-internal
network 192.168.1.0 mask 255.255.255.252
redistribute eigrp 100
neighbor 192.168.1.1 activate
neighbor 192.168.1.1 next-hop-self
neighbor 192.168.1.1 soft-reconfiguration inbound
exit-address-family
!

can you share the config of R3 and R5 let me fast correct it 

MHM

Sure, please see attached.

Clear it as below both R3 and R5 as below,still no reachabilityR3#clear ip bgp 65200

 

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