I have two layer 3 switches (Main And back up) and a palo alto firewall

main switch connects to the firewall with a routed link port(gi1/1 ip add firewall ( All connectivity is good at this point (ping successful)

Back up switch is connected to the main switch with a routed link (gi 1/1 ip main switch(gi /24 ip add

PROBLEM: Both switches are running EIGRP(Network and I can ping successfully from the back up switch to the main switch IP address the problen is I cannot ping the firewall from the backup switch(

However the vlans created on the backup switch if i connect a pc to a port assigned with that vlan it pings the firewall and routes to the internet with no problems! I just cant ping the firewall from the CLI of my back up switch. Im going bananas..lol

thank you in advance

3 Answers 3


A router (layer-3 switch, included) doesn't route from one network to the same network. If you had two different networks, one on each side, of the first switch, the layer-3 switch could route from one network to the other, and the ping should succeed.


If you are talking about L3 interfaces and EIGRP, we must assume this:

Network1: Switch1 - Firewall

Network2: Switch2 - Switch1

First. You need to set-up on your firewall EIGRP(on the way to LEARN all the routes, i thinking It don´t knows how to reach youre second switch), but, STOP, you HAVE a Palo Alto firewall, i know that EIGRP is a Cisco Propietary Routing Protocol, then, you need to set-up a DEFAULT route to Switch1(

This can be a possible solution to your issue.


Assuming this is your setup:

Backup-swi_Gi1/1 -- _Gi1/24_Main-swi_Gi1/1 -- Firewall

If you have both interfaces in routing mode on main swi, you should make sure the subnets do not overlap. This is not apparent from your question. Could you please share a bit more of the config, like the interface and routing table output on all devices?

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.