6500 VPNSM fragmentation

[m-sherman]

I have a GRE tunnel established between two 6500's with a VPNSM (12.2(18) code). During configuration, many packets were dropped at the tunnel interface due to the packet size exceeding the MTU and the DF bit set. This has been resolved and we are currently functioning without drops. However, fragmentation is still occurring. Does anyone know how to show how many packets are being fragmented at the VPNSM using a show command?

[ehirsel]

I don't have an answer for the show command yet.

However I did come across this link:

http://www.cisco.com/en/US/tech/tk827/tk369/technologies_white_paper09186a00800d6979.shtml

You may find it handy in configuring the tunnel interface and the vpnsm or msfc on the 6500 to make adjustments and implement policy routing to override the DF bit to insure that fragmented packets are non-existent, or occur occasionally.

Once I find an answer to the show command I'll post it here. In the meantime, let me know if the link I referred to is of any value to you.

[m-sherman]

Thanks for your post. We found the link helpful when we were trying to understand the issue a few weeks ago.

From what I understand, the show command is undocumented, but I would appreciate a post if you do find something.