Switch with routes that appear to be stuck

[Justin Hale]

Hi guys,

I have an issue i cant seem to fix.

i have a 3750E in the following configuration. we use this switch in a L2 configuration. e.g.

interface Vlan1

ip address 172.27.63.7 255.255.255.0

!

ip default-gateway 172.27.63.254

this switch cannot ping 2 servers i have 172.20.23.11 and 172.20.23.91. however can ping all other servers on 172.20.23.xx/24.

SWH07# sh ip route
Default gateway is 172.27.63.254

Host               Gateway           Last Use    Total Uses  Interface
172.20.23.11       172.27.62.246         0:00         10276  Vlan1
172.20.23.91       172.27.62.246         0:00        341566  Vlan1

ip routing and CEF are turned off. i have tried many things (even rebooting) but cant get rid of these 2 routes. considering IP routing is not even turned on, i cant explain how they even got there. 172.27.62.246 was the IP address of an old policy router we had. which is now gone.

has anyone even seen anything like this

[Peter Paluch]

Hi Justin,

These entries are often populated by means of ICMP Redirect messages. This table reminds me of the output of show ip redirects command - can you verify its output? If the output is confirmed then it must be that the 172.27.63.254 router sends the ICMP Redirects back to your 3750 when it receives packets for those two servers .11 and .91.

I suggest you closely verify the routing configuration of the 172.27.63.254 - it seems that there are some remainders of the old configuration still present.

Best regards,

Peter

[JMcNichol]

thanks, Pete your reply helped us we had to run a "clear IP redirect" and our issue was resolved.