nanog mailing list archives

Re: Where to buy Internet IP addresses


From: Joe Greco <jgreco () ns sol net>
Date: Mon, 4 May 2009 06:39:15 -0500 (CDT)

I think that they have to be forwarded. What do you do if people chain  
three routers? How does your actual CPE know to dish out a /60 and not  
a /64 or something? What if someone chains four? What if someone puts  
three devices behind the second?

These are weird topologies, sure, but coming up with some algorithm to  
handle some of them and not others is going to be too complicated, and  
leave some people without a workable solution.

Forwarding these requests up to the ISP's router and having several  
PDs per end customer is in my opinion the best way to go.

How is it the ISP's router is able to handle this?  Be specific.

Now explain why that can't be made to work at the CPE level.

There hasn't been a lot of consensus on exactly how this should work 
(haberman, bykim, arunt, rao, stenberg, etc). so I am conveniently
doing a bit of handwaving, perhaps.

One of the goals of providing larger address spaces was to reduce (and
hopefully eliminate) the need to burn forwarding table entries where
doing so isn't strictly necessary.  When we forget this, it leads us
to the same sorts of disasters that we currently have in v4.

... JG
-- 
Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net
"We call it the 'one bite at the apple' rule. Give me one chance [and] then I
won't contact you again." - Direct Marketing Ass'n position on e-mail spam(CNN)
With 24 million small businesses in the US alone, that's way too many apples.


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