Verio Peering Question

Thu Sep 27 19:46:19 UTC 2001

At 07:15 PM 9/27/2001 +0000, P R wrote:
 >
 >I have a quick question about Verio's public peering policy.  What is the
 >smallest size prefix that Verio will accept from public peering?  The reason
 >why I ask is because my company informed me that Verio will not accept
 >anything from a Class A address with a prefix smaller than a /20 from pubic
 >peering.  Is that true? If so, how do small ISP's work around this?

The same way they did when Sprint filtered.

If you have less than a /20, you are getting IP space from one of your 
upstreams.  The upstream announces the larger CIDR, Verio hears it, and 
sends the traffic there.  This happens even if it would be "better" for 
Verio to send it to your other upstream.

People have argued that this hurts performance on Verio's network.  It also 
eliminates the smaller ISP's ability to control traffic flows.  (e.g. You 
have a T1 to Provider-A, who gives you space, and you prepend heavily; you 
have a DS3 to Provider-B, and do not prepend.  Verio will send the traffic 
to Provider-A.)

Randy (now at AT&T, I believe) and others claim this does not hurt 
performance and that it is bad to accept small announcements.  Arguments 
include points like the routers cannot handle that many announcements, 
smaller providers flap more, etc., etc.

Of course, networks much larger than Verio (e.g. UUNET) accept /32s from 
their customers, as well as send and accept as small as /24s from 
peers.  No other network seems to have a problem with the extra 
announcements.  Verio cannot explain why these larger networks can accept 
small announcements and still run a network as well (or better) than Verio, 
but Verio insists networks should not accept small announcements.

One can make one's own judgement what this says about Verio's ability to 
run a network.

Oh, one other point - Verio accepts smaller announcements from their 
customers - and propagates them.  I guess Verio agrees that other people 
can run networks with all the extra announcements, even if Verio themselves 
cannot.

Personally, I think everyone should filter on /20s and longer - but ONLY 
FROM VERIO.  (I suggested this same things when Sprint was applying ACL 
112.)  Wonder how long Verio would continue to filter if even a few major 
networks filtered Verio's announcements.

In the end, though, it does not really matter.  As long as you have the 
larger CIDR being announced by someone, you will get the traffic in all but 
the most unusual circumstances.  (I can think of some, but they really are 
not "normal".)  You may have poor performance from Verio, but that might 
happen anyway....

 >Peter Rohrman

--
TTFN,
patrick