nanog mailing list archives

Re: Someones being naughty again...


From: Phil Howard <phil () charon milepost com>
Date: Sat, 14 Mar 1998 03:06:29 -0600 (CST)

Offhand, I can't think of any other problems but I really discourage
people from using internal address space for this purpose because it:

      - breaks stuff like path MTU discovery, etc. when filtered.

You also discourage people from filtering the ICMP packets this uses.
Right?

      - prevents easy identification of links, whose they are, etc.
        because you can't have reverse DNS and the addresses don't
        belong to you.

Not a problem if it is entirely inside an enterprise, as valid addresses
before and after it would be the same enterprise.  But as links between
I would see a problem.

      - causes confusion when multiple networks that are using such
        addresses are merged or interconnected in the wrong (right)
        way.

Private addressing is not the ideal solution, but when networks are built
with lots of links to lots of places, address allocating authorities
prefer you to use private addresses where feasible.  It maybe be a gray
and fuzzy line determining that, but many cases clear work fine with
such addresses (for example having a consisent MTU).


I like the idea behind why you would do it, but... can't justify it.

I don't have so many links that I can't get them all in a /24.  But much
beyond that and I will be using private addresses.  I do run some private
address LANs, but they end in private addresses and you should never see
them (but if you are my customer you will be able to).

-- 
Phil Howard | stop8810 () spammer6 net stop6589 () spammer3 net no1way64 () no3where edu
  phil      | no3spam1 () noplace4 edu no3spam5 () anywhere com crash431 () s8p1a7m3 com
    at      | blow2me8 () no83ads9 org stop7363 () dumb7ads edu suck6it9 () no1place net
  milepost  | end8it30 () noplace0 com no2spam5 () anyplace org a1b5c1d8 () s3p3a5m0 edu
    dot     | no52ads8 () no97ads7 com die9spam () noplace0 org end0it22 () spam9mer edu
  com       | stop3424 () no2place net eat38me1 () lame9ads org end2ads8 () nowhere8 org


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