Internet disruptions on multi-access networks, NAT and proxy caches

[Sean Donelan <sean () donelan com>]

Overall Internet performance measurements show only the typical
variations in Internet performance.  However, there have been
several severe, but localized disruptions in multi-access networks,
such as local ethernet, token ring and cable modem networks.
There are also difficulties with some NAT devices and networks
which aggressively use proxy web caches, such as international
ISPs with small uplinks.

This is a side-effect of Code Red II scanning the local subnet or
network, and some network equipment having difficulty managing
the ARP, NAT or proxy cache resource exhaustion.

Due to the way IP forwarding works, point-to-point backbone router
links are more or less immune to the problem. So I don't expect to
see impact on the global Internet.  But local enterprises and tier
2 through N ISPs could have problems with misbehaving servers on
their networks.