[189050] in North American Network Operators' Group
RE: BGP peering strategies for smaller routers
daemon@ATHENA.MIT.EDU (Tony Wicks)
Mon May 2 17:03:43 2016
X-Original-To: nanog@nanog.org
From: "Tony Wicks" <tony@wicks.co.nz>
To: "'NANOG list'" <nanog@nanog.org>
In-Reply-To: <D521F7D6D2FA354D80F0D6AB960949F70724EC6D@N10OS2CE14CN1.N10.tconet.net>
Date: Tue, 3 May 2016 09:03:18 +1200
WTL-MailScanner-From: tony@wicks.co.nz
Errors-To: nanog-bounces@nanog.org
I have used variations Gustav's solution below to good effect as well, =
this also works with two smaller routers providing basic fail over and =
load balancing. I found its best to take Full + default from one =
provider and just default from the other. Set a higher local-pref on the =
default only provider than the full+default one, then filter the =
full+default routes by AS-path as desired. Incoming control via the =
normal prepending of outgoing advertisements.
-----Original Message-----
From: NANOG [mailto:nanog-bounces@nanog.org] On Behalf Of Gustav Ulander
Sent: Tuesday, 3 May 2016 8:30 AM
To: Mike <mike-nanog@tiedyenetworks.com>; NANOG list <nanog@nanog.org>
Subject: RE: BGP peering strategies for smaller routers
Hello.
When we was in a similar situation we opted for one transit provider to =
provide a default to us then we filtered on AS-HOPS so prefixes that was =
more than 3 hops away was denied.=20
This way we got the ones that where closest to us and that where more =
likely to matter. Prefixes that=E2=80=99s more than 3 hops away on both =
links could probably just as well go on a default insteed.=20
However it=E2=80=99s a rather crude way of fixing the issue. We just did =
it to have the router up while we got extra memory from it. (we had =
memory shortage after an update that we needed to apply to correct some =
bug I think. We couldn=E2=80=99t just rollback the update if my memory =
serves me correct.)=20
//Gustav
-----Original Message-----
From: NANOG [mailto:nanog-bounces@nanog.org] On Behalf Of Mike
Sent: den 2 maj 2016 21:07
To: NANOG list <nanog@nanog.org>
Subject: BGP peering strategies for smaller routers
Hello,
I have an ASR1000 router with 4gb of ram. The specs say I can get
'1 million routes' on it, but as far as I have been advised, a full =
table of internet routes numbers more than 530k by itself, so taking 2 =
full tables seems to be out of the question (?).
I am looking to connect to a second ip transit provider and I'm =
looking for any advice or strategies that would allow me to take =
advantage and make good forwarding decisions while not breaking the bank =
on bgp memory consumption. I simply don't understand how this would =
likely play out and what memory consumption mitigation steps may be =
necessary here. Im open to ideas... a pair of route reflectors?=20
selective bgp download? static route filter maps?
Thank you.
Mike-
