Re: [SPAM] Re: [SPAM] Your daily internet traffic report

[Hugo van der Kooij <hvdkooij () vanderkooij org>]

On Sat, 16 Oct 2004 lee.e.rian () census gov wrote:

> > > Most routers will regard any ICMP request to them as a low priority
> issue.
> > do they? icmp is not only about 'echo'. there's lot of
> > other functions via type/code - fragmentation, mtu etc,
> > vital for traffic signalization. administrators, who
> > blindly closes all icmp traffic are plain stupid idiots.
>
> Lots 'o flame but no light.
>
> How about sharing your knowledge of why certain icmp traffic should be
> allowed and the risks associated with allowing that traffic?

Just to name one: Path MTU discovery (RFC 1191)

   This memo describes a technique for dynamically discovering the
   maximum transmission unit (MTU) of an arbitrary internet path.  It
   specifies a small change to the way routers generate one type of ICMP
   message.

Hugo.

-- 
        I hate duplicates. Just reply to the relevant mailinglist.
        hvdkooij () vanderkooij org             http://hvdkooij.xs4all.nl/
                Don't meddle in the affairs of magicians,
                for they are subtle and quick to anger.

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