[c-nsp] ICMP Mask Requests on 6500

[John Neiberger]

This is an interesting one. I have a TAC case open, but I thought I'd
check to see if anyone had ever seen this before. We had some old
equipment that uses ICMP mask requests to get its subnet information.
When this equipment is connected to an old 7513 running 11.1 code, the
router replies to the mask request with an ICMP mask reply. When we
move that device to a 6513 (Sup720, 12.2 code) we can see the mask
request come in, but the 6500 never sends a reply. According to Cisco,
the code to do the reply is in the IOS, 12.2(18)SXF9, so it must be a
bug. However, it also didn't work in 12.2(33)SXI5.

I'm beginning to think the code is actually being deprecated since no
one really uses this feature any more. Have any of you ever had to
deal with ICMP mask requests and replies before?

Thanks!
John