show ip route 1

[Michoud]

I have a Cisco WS-C3750-24TS switch that has some routes in it but I can't figure out where the routes came from.

This is the output from a show ip route:
switch2#show ip route
Default gateway is 10.2.2.6
Host Gateway Last Use Total Uses Interface
10.101.1.51 10.2.2.1 0:00 288410 Vlan1
10.255.254.223 10.2.2.1 0:00 315333 Vlan1
switch2#


But when I do a show start or show run I can't see where the routes are configured. The only thing in the config related to routing is: ip default-gateway 10.2.2.6

Any comments are appreciated.

 

[vipergg]

If its using a default gateway then routing is not turned on and it is being used as a layer 2 switch.

 

[Michoud]

It is definitely using those two other routes. I just don't now where it gets the routes from. I'm sure it's statically defined, I just don't know where.

 

[vipergg]

If its using those routes then it has to be in the config or you have a dynamic routing protocol turned on such as ospf or eigrp.

 

[ISPKing]

That is layer 2 route output, check your interface assignments, that is not the output received when when iprouting is on.

CCNP

 

[Michoud]

ISPKing,

What do you mean check the interface assignments?

 

[ISPKing]

Do you have those assigned anywhere else, like a secondary possible on the vlan1 interface.

CCNP

 

[Michoud]

When I do a show run I don't see any line that has 10.101.1.51 in it.

Any suggestions on where else to look?

 

[ISPKing]

do a sho ip redirects.

CCNP

 

[Michoud]

This is what I get from a sho ip redirects:
Default gateway is 10.2.2.6
Host Gateway Last Use Total Uses Interface
10.101.1.51 10.2.2.1 0:00 293949 Vlan1
10.255.254.223 10.2.2.1 0:00 318697 Vlan1

What can I do to get rid of one of these entries?

 

[ISPKing]

Ah ok, makes sense. Your default gateway which i presume is 10.2.2.1 is sending out redirects to your hosts connected to the switch and other hosts requesting a certain subnet. This is perfectly ok unless you don't want this to happen (very few reasons not too), I do not know your topology per say, but this is normal...Thing is i am unsure as to why the switch has piked them up. Just make sure you can vouch for those addresses.

Here is the command to turn this off in the router, but note if you have more then one subent behind a router on a signal interface you will not be able to route between those networks.


(config)#no ip icmp redirect



CCNP

 

[Michoud]

That did it. Thank you very much ISPKing!

 

[ISPKing]

Np.

CCNP