MAC Table and ARP resolves but Default gw unpingable

[birdiebert]

Hi there,

I have a fairly simple but peculiar problem at hand.

A device with a static IP located on an access port on an L2 switch which trunks back to a router with the same vlan interface. Show mac address-table on the L2 sw shows that the mac address is being learned by the switch as expected. Sh mac address-table and ip arp on the router tells us that the mac address is seen coming from the correct interface and ip is resolving correctly as well.

But I for the love of the universe can't figure out why the gateway can't ping the device and vice versa. Show interface does not show any errors. Other devices on the same switch and same vlan are perfectly pingable and working fine.

Someone please enlighten me. Thank you.

[Richard Burts · Accepted solution]

Is it possible that a firewall on the device is preventing ping? Can this device ping other devices in the network? Can other devices in the network ping this device? Are you sure that the mask on the device is correct? Can you post the output of ipconfig from the device and the output of show arp from the router?

HTH

Rick

[birdiebert]

Hi Richard,

Thanks for your answer.

It's a bit hard for me to troubleshoot from the device end as it is not a computer and we not permitted access to it, it's managed and configured by some other team/department, so I cannot answer your question whether the device can ping other devices on the network. I will try to find another device from the same subnet to ping it other than the default router and get back to you with this.

Mask is a regular /24, but since it's not configured by me I can only trust that the configuration is correct. I have communicated with the dept managing the device and obtained the mac address from them and it matches the one I'm seeing in the arp/mac table.

I will get back to you with more info when I get back to work but thanks for your suggestions so far.

Edit: No there is no firewall in between.

Bert

[birdiebert]

You can pretend nothing happened.

I came back to work this morning and everything was working fine.

Ah~ the wonders of networking.

Thank you very much for your help though. I appreciate it.