NAP/ISP Saturation WAS: Re: Exchanges that matter...

Dima Volodin dvv at
Mon Dec 16 21:00:09 UTC 1996

More of that - at least one site uses one of our hosts as a target of
pings for measuring "Internet health".  We consider this to be an abuse
of our resources and, most probably, we will disable any external
traffic we find inappropriate for this or other hosts.


dave o'leary writes:
> At 2:52 PM -0500 12/16/96, Mike Leber wrote:
> >On Sun, 15 Dec 1996, Forrest W. Christian wrote:
> [stuff cut]
> >The loss is caused by atleast three things:
> >
> >* ICMP packets are dropped by busy routers
> >
> >Many routers drop ICMP packets (ping, traceroute) when busy, or alternate
> >dropping ICMP packets.  I know that this behavior occurs when the packets
> >are directed to the specific router, I am not sure if this every occurs
> >for packets passing through.  The standby tool ping needs a more reliable
> >replacement for testing end to end packet loss.
> in general the router isn't going to treat one protocol (i.e. protocols
> running over IP (TCP, UDP, ICMP) differently when the packets are passing
> through the router - it just looks at the header and forwards.  ciscos do
> handle pings for which the router itself is the destination at a lower
> priority than packets going through the box.  I'll leave the discussions
> as to whether ping is adequate or not for another time....
> [more stuff cut]
> 					dave

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