[c-nsp] Secondary IP address causing MTU reduction?

David Coulson david at davidcoulson.net
Tue Dec 16 21:28:01 EST 2014

What platform? What code?

Can you post your interface config?

Sent from my iPhone

> On Dec 16, 2014, at 9:22 PM, Eric A Louie via cisco-nsp <cisco-nsp at puck.nether.net> wrote:
> I encountered a strange problem that I'm hoping is a bug.
> Directly connected routersMTU 9200Works fine with single IP addresses
> As soon as I put a secondary address on both interfaces (one VLAN, one physical interface), the MTU allowed magically decreased to 1477.  1500 byte packets with DF set would not pass.
> Removing the secondaries fixed the problem.
> Anyone seen this before?
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