04-28-2017 03:12 AM - edited 03-05-2019 08:26 AM
Hi,
Im having an issue with getting an ospf summary address appearing in a routing table of an ASBR.
Topology is:
(BGP-NETWORK)-(WAN-RTR)--(ASBR)--(OSPFNETWORK)
I am trying to summarize the 10.0.0.0/8 network on the ASBR so I can export a 10/8 summery address into the BGP network.
config from the ASBR is :
router ospf 100
log-adjacency-changes
summary-address 10.0.0.0 255.0.0.0
redistribute connected subnets
network 10.0.0.0 0.255.255.255 area 0
!
router bgp 65000
no synchronization
bgp log-neighbor-changes
redistribute ospf 100 match internal external 1 external 2
neighbor 192.168.10.2 remote-as 65001
no auto-summary
!
The following is the routing table output - no summery address is getting installed ....
ASBR1#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
192.177.58.0/32 is subnetted, 1 subnets
B 192.177.58.9 [20/0] via 192.168.10.2, 00:19:54
C 192.168.10.0/24 is directly connected, FastEthernet1/0
10.0.0.0/29 is subnetted, 4 subnets
O 10.39.54.24 [110/20] via 10.39.54.17, 00:14:43, FastEthernet0/1.3652
C 10.39.54.16 is directly connected, FastEthernet0/1.3652
O 10.39.54.8 [110/20] via 10.39.54.1, 00:14:43, FastEthernet0/0.3650
C 10.39.54.0 is directly connected, FastEthernet0/0.3650
!
What am I missing ???
Thanks
04-28-2017 04:07 AM
Hello,
what is the output of 'show ip bgp' ?
You should see the summary route in there.
04-28-2017 05:49 AM
Hi
it looks like you are not receiving the prefixes 10.x.x.x through BGP or other routing protocols into the routing table, so the problem could be on the BGP or any restriction on the path.
Summary-Address is used when you are advertising a prefix known through external routing protocols.
04-28-2017 05:55 AM
Hi,
I want to summerize my ospf into BGP.
I am recieving ospf routes in the 10.x.x.x range as shown :-
Gateway of last resort is not set
192.177.58.0/32 is subnetted, 1 subnets
B 192.177.58.9 [20/0] via 192.168.10.2, 00:19:54
C 192.168.10.0/24 is directly connected, FastEthernet1/0
10.0.0.0/29 is subnetted, 4 subnets
O 10.39.54.24 [110/20] via 10.39.54.17, 00:14:43, FastEthernet0/1.3652
C 10.39.54.16 is directly connected, FastEthernet0/1.3652
O 10.39.54.8 [110/20] via 10.39.54.1, 00:14:43, FastEthernet0/0.3650
C 10.39.54.0 is directly connected, FastEthernet0/0.3650
ASBR#sh ip ospf sum
OSPF Process 100, Summary-address
10.39.54.0/255.255.255.0 Metric 16777215, Type 0, Tag 0
04-28-2017 06:01 AM
Have you tried to redistribute the summarized network into BGP?
Example:
ip prefix-list TEST seq 5 permit 10.0.0.0/8
route-map TEST permit 1
match ip address prefix TEST
router bgp 65000
redistribute ospf 100 route-map TEST match i n e
*summary-address is used for OSPF environment only, it will not work if you want to advertise a summarized prefix to other routing protocols.
04-28-2017 06:07 AM
Yes, this still wont work.
Ok, so how will i be able to advertise a summery route into bgp from ospf??
04-28-2017 06:13 AM
Just for testing (if it is not on production)
include the line on the ASBR
ip route 10.0.0.0 255.0.0.0 null0 tag 5
tag 5 is optional is just to avoid be redistributed into your OSPF 100 process.
04-28-2017 06:15 AM
And add either "network 10.0.0.0 mask 255.255.255.0" or "redistribute static" under your BGP configuration.
Jon
04-28-2017 08:41 AM
Hi guys
Thanks for the responses but I have found the solution
I am going to issue a bgp aggregate address from the wan router summarising the ospf range - this removes the need for the ospf summary
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