Remote switch management - Routing

[IS34lyf]

I have an issue where i could not ping a remote switch on our network. I have the remote switch configured with ip default gateway and i can ping the DG from the switch. Anything outside of the DG from the switch perspective is unreachable.

The DG can reach the outside network and the inside network. I know im missing something very simple here but i couldn't figure it out. Please help.

[Flavio Miranda · Accepted solution]

Hi

 Instead of the ip default gateway command, add a static route:

ip route  0.0.0.0   0.0.0.0. "gateway"

[Richard Burts]

The original post is pretty vague about the environment. The drawing shows what appears to be a user at 192.168.1.10 which connects to a switch which has interfaces in 192.168.1.0 and in 172.16.100.0 and connects to a switching 10.5.5.0. With the route statements indicated in the drawing I would expect that the user in 192.168.1.0 should be able to access resources in 10.5.5.0.

If that is not the case then we need additional information to be able to understand the issue and to give good advice. As a start please provide identification for each switch, and more specifics about which device does have reachability and which device does not. Configs of the switches would provide good detail for us to work with.

The drawing suggests that the lower switch and the middle switch are operating as layer 3 switches. Can you confirm that this is the case? The operational mode of the upper/right switch is not clear. Can you clarify whether it is layer 2 or layer 3?

[IS34lyf]

Hello,

Thanks for the suggestions. I attached an updated network diagram that has scenarios and more info requested. Let me know if there's anything else i can add. This is exactly how it sits now in the office. The way i ssh into the L3Sw3 is through L3Sw2.

[MHM Cisco World]

trunk between SW2 and SW3 are it run as trunk or access mode ?
trunk are allow native VLAN & VLAN 5?
trunk native VLAN is same ?

what I think is native VLAN mismatch or something around native VLAN, 

please if you can also do trace route from PC to SW and from SW to PC.

[Richard Burts]

Thank you for the improved diagram and specifics of what does and what does not work. I find it very puzzling that the layer 2 switch can successfully ping 172.16.100.1 but can not ping 192.168.1.1 which is another interface on the same switch. If ping to 172.16.100.1 is successful then the default gateway of L3SW3 must be working. But why would access to another interface of the same switch not work? I think we need to see switch configurations, at least of L3SW1.

[Jon Marshall]

What is equally, if not more, puzzling is that the L2 switch can ping Sw1 but Sw1 cannot ping the L2 switch. 

I agree we need to see the configs of at least those two switches. 

Jon

[IS34lyf]

My guess would be because the device is L3 and it required 'ip route' command instead of 'ip default-gateway' for L2? I dont know, I've been using 'ip default-gateway' command on our old 2960x switches. But it works now with the ip route command.

[Flavio Miranda]

It is a very good guess, actually I did not think about it before. But, I did this suggestion for you because I had this  very same problem in the past. I was using ip default-gateway with no sucess and then ip route worked.

 Glad you made it.