Scanning activity from 2620:96:a000::/48

Tore Anderson tore at
Tue Jul 6 10:45:31 UTC 2021

* Dobbins, Roland

> Scanning is part of the ‘background radiation’ of the Internet, and it’s performed by various parties with varying motivations.  Of necessity, IPv6 scanning is likely to be more targeted (were your able to discern any rhyme or reason behind the observed scanning patterns?).

The pattern appears to be sending a bunch of ICMPv6 pings to a random adresses
within the same /104. The last 24 bits of each destination address appears
randomised in each ping request, that is.

I don't know if they move on to another /104 after they were done with the
first one and so forth.

> iACLs, tACLs, CoPP, selective QoS for various ICMPv6 types/codes, et. al. should be configured in such a manner that 600pps of anything can’t cause an adverse impact to any network functions.  Because actual bad actors are unlikely to voluntarily stop, even when requested to do so.

Clearly, and in this particular case my CP protections did their job
successfully, fortunately, but that is kind of besides the point.

What I am wondering, though, is if it is really should be considered okay for
a good actor to launch what essentially amounts to an neighbour cache
exhaustion DoS attack towards unrelated network operators (without asking
first), just because bad actors might do the same.


More information about the NANOG mailing list