Someone on another forum told me that Win2K uses ICMP to negotiate the

MTU size which can really affect performance if the MTU gets
negotiated
too high. They also said that if ICMP was "totally blocked" by my
routers
then the Win2K MTU negotiation would not work right.

My question, what packet filter exception would I have to create to
get
this to work?

Any ideas?

Thanks in advance.