Re: ICMP Packets.

[jrg () gbnet net (James R Grinter)]

On Tue 2 Jun, 1998, Henry Hertz Hobbit <hhhobbit () icarus weber edu> wrote:
> said it before, if you don't need it, block it, both ways. In
> other words, this applies to *everything*. If you don't NEED
> the ICMP packets (all of them, not just the echo/echo-reply)
> to go out, block them. Your actual needs, not somebody else's

this is sound advice - but - beware of ICMP packet types that are
fundamental to the correct operation of some protocols.

('path MTU discovery' leaps to mind here, as one thing that is blocked
in many places seemingly without regard to what that will break. If you
don't know what this does and what the implications are, this is a good
time to go and research.)

James.