do bogon filters still help?

Florian Weimer fw at deneb.enyo.de
Wed Jan 11 20:36:37 UTC 2006


* william elan net:

>> You should move 192.88.99.0/24 from SPECIAL to YES (although you
>> shouldn't see source addresses from that prefix, no matter what the
>> folks at bit.nl think).  169.254.0.0/16 should be NO (otherwise it
>> wouldn't be link-local).
>
> I think you just explained it yourself why this is "SPECIAL", i.e.
> routing of it depends on local policies and setup. Anything where it
> is not clear from RFCs if it should be routable or not and where it 
> depends on local decisions & policy is what I called SPECIAL.

Uhm, no.  6to4 anycast only works without hickups when the prefix is
NOT treated in any special way. 8-) That's part of its charm.  If
operators start to install special filters, they break this
functionality for no real gain.

>> I haven't looked at RFC 3330, but another RFC reserves 192.0.2.0/24
>> for examples in documentation.  In practice, this prefix is used for
>> distributing fake null routes over BGP, so it's a rather strong NO.
>
> If you know which RFC it is, I'll update the reference table.

Uhm, looks like I was mistaken.  Each time the topic comes up, I
confuse this with RFC 2606 (domain names).  No such RFC exists for
IPv4 addresses.



More information about the NANOG mailing list