IP routing command

[iores]

Hi,

I have two switches with GRE tunnel between them.

When I ping SVI on sw2 from sw1, everything works.

When I ping the host behind that SVI on sw2, ping fails.

However, when I enable ip routing on sw2, ping to host works. 

How is this possible?

Sw1 has enabled IP routing, however, I am only using static routes to rute the traffic through the tunnel.

[MHM Cisco World]

Do you config GW in client?

If yes and it not work share config in both SW

MHM

[iores]

Yes, client has correct def. gw.

[MHM Cisco World]

Share traceroute from both clients in  both side 

MHM

[iores]

When tracerouting to SVI (host def. gw.) everything is OK. When tracerouting host itself, it seems like nothing hapens but the switch has static route through the tunnel towards host subnet and the output of show ip cef confirms this, too.

[MHM Cisco World]

Cleint1-SW-GRE-SW-Cleint2
I need to see traceroute from client1 to clinet2 
and see traceroute from cleint2 to cleint1

share here 

thanks 

MHM

[Flavio Miranda]

Hi

 If you run  ip routing on the switch you are enabling the routing table on it. This is required for a switch to perform routing otherwise it will act as Layer2 device only

[iores]

And that is why is this even more confusing.

[Flavio Miranda]

This is required in order for switch be able to perform routing. If you use a router instead  you dont need to worry with that.

[Richard Burts]

There is much that we do not know about this environment and that makes it difficult to give good advice. So posting the configuration of both switches would be helpful. 

But based on the little that we know I have this comment:  if sw2 does not have ip routing enabled then a host in vlan x can only communicate with other hosts in that vlan. It seems a pretty safe assumption that anything on sw1 is not in the vlan of the host on sw2. So to be able to effectively use the GRE  tunnel sw2 requires that ip routing be enabled.

[iores]

On sw2, I pinged the host in vlan A from SVI B (on sw2) with ip routing disabled.

I will try to get the configs.

[Richard Burts]

I am not clear when you say "On sw2, I pinged the host in vlan A". Was this access while you were on the console? On a telnet/SSH connection on sw2? Of from a host on sw2? If sw2 has the configuration statement ip default-gateway then the switch (and connections through console or telnet/SSH should be able to reach remote addresses. The real question is how hosts connected to vlans on sw2 would reach any remote destination.