Mailing List Archive

Stuck null0 route
Hi all,

I was testing out blackhole communities on a new FESX648-PREM.

My setup was as follows:

router bgp
!
redistribute static route-map blackhole
!
!
route-map blackhole permit 5
match tag 66
set community 55555:666

And I triggered the blackhole with:

ip route 123.123.123.123 255.255.255.255 null0 tag 66

Possibly some invalid configuration in there... but nevertheless I applied
it and the IP became nullrouted.

I then removed the ip route with "ip route 123.123.123.123 255.255.255.255
null0 tag 66", but it was strangely still nullrouted.

I then remove the entire configuration (redistrbute, route-map, etc),
cleared the BGP session with my upstream provider, and it was still
nullrouted.

When I run a "show ip route 123.123.123.123" the correct destination,
netmask, gateway and port are shown. Similar result with a "show ip bgp". I
wrote my config and displayed it with a "show config" -- no sign of the
nullroute anywhere.

Running a traceroute to the IP shows that it gets nullrouted as soon as it
hits the switch. Other servers connected on the same switch and VLAN cannot
ping the IP.

Anyone know what might cause a nullroute to get stuck like this?

- Elliot