RFC 1918 addresses

Mon Jun 2 20:01:19 UTC 1997

Paul,

>> I agree that ever having a source or destination IP that's RFC1918 outside
>> the domain is a very bad thing.   

>I don't see anyone here disagreeing with that, but apparently a number of
>ISP's did not consider the ICMP case when they gave numbers to their T1's,
>and so it's a question of definition rather than of intent.  Transit nets
>are public, not private, and so they have to have public, not private,
>addresses.

I want to respectfully disagree.  I do run internal routing protocols
that can't handle VLSM or CIDRization permitting cutting up a class C
into 64 disconnected pieces. , igrp in particular.  Because of this I
would burn too many network numbers by having to use public network
numbers for all my T1's.  I never permit a case where both sides of a
router have RFC1918 address space so there is no confusion in a
traceroute at to where to address questions about routing issues.
Purity of addresses is valuable but I am willing to compromise on this
in this instance.

Walt