Level 3 BGP Advertisements

Wed Aug 29 19:52:10 UTC 2012

No, that's not standard practice.  I do this exact thing with Level 3 and have been for many many many years.  Whoever is telling you this must be green.

I would recommend adding the no-export community to your more specific routes if you can so as to be a good steward of the ever growing Internet IPv4 table.
________________________________________
From: Nick Olsen [nick at flhsi.com]
Sent: Wednesday, August 29, 2012 2:28 PM
To: nanog at nanog.org
Subject: Level 3 BGP Advertisements

Greetings all.

In practice, We've always advertised our space all the way down to /24's
but also the aggregate block (the /20 or the /21). Just so there was still
reachability to our network in the event that someone made the foolish
mistake of filtering lets say prefixes smaller /23...

Anyways, I've always thought that was standard practice. And its never been
a problem. Until we brought up peering with level 3..

I noticed that while the /24's made it out to the world. The larger
counterparts (2 /21's and a /20) did not. So, I start sniffing around. Find
that I do indeed see the prefixes in Level 3's looking glass but they
aren't handing it off to peers. So, Naturally, I land on this being some
kind of prefix filtering issue and open a ticket with Level 3. They tell me
this is standard practice. And If I want to see the /20 or /21's make it
out to the rest of the world, I need to stop sending the /24's.

Does this sound normal?
Is what I'm doing (Advertising the aggregate prefix) a good rule of thumb?

Any other thoughts?

Nick Olsen
Network Operations (855) FLSPEED  x106

----------------------------------------------------------------------
This email message and any attachments are for the sole use of the intended recipient(s). Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message and any attachments.