04-16-2013 09:29 PM - edited 03-04-2019 07:37 PM
I'm testing a config in my lab and having some problems. What I want is for router R3 to inject a default route into OSPF only if the network 1.1.1.1/32 is in R3's routing table. When I no-shut the loopback interface on R1 I see the route show up in R3's routing table and then I see the default route appear on R4. The problem is, when I shutdown the loopback interface on R1, I see the route 1.1.1.1 disappear from the routing table on R3, but the default route still shows up on R4. I'm using a route-map with a prefix-list on R3 to set the condition for advertising the default route.
Why doesn't the default route on R4 disappear when the 1.1.1.1 network drops off of R3's routing table?
here's the configs:
R1
interface Loopback0
ip address 1.1.1.1 255.255.255.255
shutdown
!
interface FastEthernet0/0
ip address 10.1.13.1 255.255.255.0
duplex auto
speed auto
!
router bgp 100
no synchronization
bgp log-neighbor-changes
network 1.1.1.1 mask 255.255.255.255
neighbor 10.1.13.3 remote-as 300
no auto-summary
!
R3
interface Loopback0
ip address 3.3.3.3 255.255.255.255
!
interface FastEthernet0/0
ip address 10.1.13.3 255.255.255.0
duplex auto
speed auto
!
interface FastEthernet2/0
ip address 192.168.34.3 255.255.255.0
duplex auto
speed auto
!
router ospf 1
log-adjacency-changes
network 192.168.34.0 0.0.0.255 area 0
default-information originate route-map default-route
!
router bgp 300
no synchronization
bgp log-neighbor-changes
neighbor 10.1.13.1 remote-as 100
no auto-summary
!
ip prefix-list check-default seq 5 permit 1.1.1.1/32
!
route-map default-route permit 10
match ip address prefix-list check-default
!
R4
interface FastEthernet0/0
ip address 192.168.34.4 255.255.255.0
duplex auto
speed auto
!
router ospf 1
log-adjacency-changes
network 192.168.34.0 0.0.0.255 area 0
!
04-16-2013 09:46 PM
You stated that the 1.1.1.1/24 is disappearing from R1, but is the 1.1.1.1/24 route being removed from R3's route table?
Sent from Cisco Technical Support iPhone App
04-16-2013 09:58 PM
Yes- the route disappears from R3's routing table.
04-16-2013 10:15 PM
Hi Frank,
does the behavior change when you use the always-option:
default-information originate always route-map default-route
Best regards
Rolf
04-18-2013 04:58 AM
Hello Frank,
I tried your configuration in GNS and everything was working as expected.
Best Regards
Please rate all helpful posts and close solved questions
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide