I saw it version of this earlier: Enter configuration commands, one per line. End with CNTL/Z. Router(config)#ip route clueless No seriously.. What if that customer has a VPN design with a dial backup behind their firewall. Using BGP to suck down a default route from the provider, when that default route goes away, then the internal router initiates the dial backup solution to the remote network. They should not be sending out any BGP routes though.. But.. See example above... OR They are in the process of preparing for Multi-homeing and just have not got it up yet... You know one provider is toiling with the T-1 facility FOC etc.. Sure this is somewhat unusual, but I have seen it, and corrected it... Jim
It would be nice if vendors had a variant to (in cisco terms) ip verify unicast reverse-path that would work in asymmetrical networks. If you only have a single link to the internet, the command works well, but then why would you ever run bgp for a single uplink?
-Jack