MTU issue

[NAVIN PARWAL]

Folks,

we have a 7600 series router with a card that does not support changing the mtu to more than 1500.

When we ping from CE's, everything seems fine, an extended ping with the DF bit to 1 and MTU of 1508 fails, which i would suspect.

My question is that why does the router not increment giants counter under the interface when i do the test mentioned in the previous paragraph.

When we go to some webpages the counter increases. It appears that some webpages require views not to defrag the packets?? as a result we can not get to the pages when going through the mpls network? like msn.com

i would imagine that i could reproduce the same result by doing a ping with MTU higher that 1500 and setting the DF bit to yes, but i am not, packet gets droped but the giant counter does not increment.

any ideas?

i will surely rate this post.

thanks

[romccallum]

instead of just batting out the answer straight off how about lets look at what protocol you are using with your web pages and what protocol you are using while pinging. This will defo give you the reason as to why you see the counters. Also have you tried mpls mtu on the interfaces?