Your company's network follows a standard three tier hierarchical desing (Core, Distribution, Access) and a WAN module that consists of two border routers, each having a separate connection to different ISPs (eBGP sessions running with the ISPs).
Inside your network, you run OSPF with a flat Area 0 everywhere. Between the Border Routers and the Core routers you run iBGP 200 with next-hop-self used on BRs towards the CORES.
The ISP sends you a default route via BGP. You want to push a default route down to the Distribution routers and you configure command
For some reason, the Distribution does not get the default route from Core:
CORE# sh ip route... Gateway of last resort is 192.168.255.1 to network 0.0.0.0 192.168.255.0/32 is subnetted, 2 subnets C 192.168.255.2 is directly connected, Loopback0 O 192.168.255.1 [110/2] via 192.168.1.1, 00:49:25, FastEthernet0/0 192.168.1.0/30 is subnetted, 2 subnets C 192.168.1.0 is directly connected, FastEthernet0/0 C 192.168.1.4 is directly connected, FastEthernet0/1 B* 0.0.0.0/0 [200/0] via 192.168.255.1, 00:49:20
DIST# sh ip route... Gateway of last resort is not set 192.168.255.0/32 is subnetted, 2 subnets O 192.168.255.2 [110/2] via 192.168.1.5, 00:49:43, FastEthernet0/0 O 192.168.255.1 [110/3] via 192.168.1.5, 00:49:43, FastEthernet0/0 192.168.1.0/30 is subnetted, 2 subnets O 192.168.1.0 [110/2] via 192.168.1.5, 00:49:43, FastEthernet0/0 C 192.168.1.4 is directly connected, FastEthernet0/0
* Note that the output does not show any info about the right-hand side routers (gray colored in the diagram)
What is the problem? How to solve it (without splitting the OSPF into separate areas) ?
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