Netonix Forums

My client has IS-IS configured on his router,we connected their link with fiber to netonix-ws-12-250-DC, the link come up but no traffic ,we changed the MTU to match the client but to no avail, does this switch have issues with such protocol......puzzling!!!

if the link is connected directly (bypassing the switch) it works.

thanks to help.

What is the MTU on the router/client and on the switchports?

Try increasing the MTU on the Netonix - e.g. by 100 (at least 18 or 22).

Netonix will show the size including the ethernet frame header etc., but your router probably doesn't include this part.

For standard 1500 byte packets - if I remember correctly:
1472: This is the max. size as a parameter for ping on Windows etc. (the IP header is not included)
1500: This is the max. size for ping on a Cisco router etc. (IP header included)
1518: This is the frame size
1522: This is the frame size if you have added a vlan-tag

You can use default MTU on recent firmware, 1528 I think, with 1500 MTU on other devices. You can even set it higher just to be sure since it won't drop lower size paquet, just the ones that are over MTU.

I'm not familliar with IS-IS but I would also try enabling / disabling multicast and test with dhcp snooping disabled if enabled, juste in case.

Also, make sur you have last firmware.