nanog mailing list archives

Re: rfc1918 ignorant (fwd)


From: "Stephen J. Wilcox" <steve () telecomplete co uk>
Date: Thu, 24 Jul 2003 11:22:49 +0100 (BST)



On Wed, 23 Jul 2003, Haesu wrote:

Well, if uBR showing RFC1918 address out on the traceroute is an issue, why not
just reverse the way its configured?

Put RFC1918 as secondary, and put the routable addr as primary. Either way, it
should work w/o issues, right?

Hmm this could affect routing protocols which use the primary address.. 

I know quite a few people who purposely put a non-routable IP (whether it be
1918 or RIR-registered block) as primary on their interface, and use routable
IP as secondary. Their reason for doing this is to somewhat "hide" their
router's real interface IP from showing up in traceroute.. Well, it wouldn't 
completely 'hide' it, but to a certain level of degree, it probably does...

Right but this one benefit doesnt make right the wrongs!

I guess one thing you could do (if you really wanted to implement hacks) is to 
use the rfc1918 space on your routers and then nat them to a global ip at your 
borders.. achieves all your goals anyhow (not that i'd recommend it ;)


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