[193364] in North American Network Operators' Group
RE: BGP Route Reflector - Route Server, Router, etc
daemon@ATHENA.MIT.EDU (Emille Blanc)
Thu Jan 12 19:25:53 2017
X-Original-To: nanog@nanog.org
From: Emille Blanc <emille@abccommunications.com>
To: Justin Krejci <JKrejci@usinternet.com>,
=?windows-1255?Q?NANOG_=FD=5Bnanog=40nanog=2Eorg=5D=FD?= <nanog@nanog.org>
Date: Thu, 12 Jan 2017 16:25:47 -0800
In-Reply-To: <3E9C67DA261AC349B60FF3609F5E211D7D80357D@USI-2K10EX02-MT.usicorp.usinternet.com>
Errors-To: nanog-bounces@nanog.org
> I am thinking things like OpenBGPd and BIRD could make a good route refle=
ctor though they are most often discussed in the context of IXPs (ie eBGP s=
essions).
We use openbgpd - well, the native OpenBSD equivalent - for route-reflectio=
n in a couple of places, as well as a full bgp feed for at least one site, =
using (old) Poweredge 1950 Gen2's. They were on-hand, so the price was righ=
t.
It's not caused us any grief to date. That said, neither have our 7204VXR's=
which do the same thing in some areas.
Needless to say, we don't use the reflectors to actually move the bits, but=
have at least on one occasion measured ~88,000pp/s out of one of the 1950'=
s that takes a full feed, before interrupts were starting to look worrisome=
on old non-smp safe code.=20
But switches with bgp or ospf support are cheap provided you're not feeding=
them with a full table.
Convergence times haven't been a problem for us, but we're only hovering ar=
ound 1500 routes at the moment.
Having something you can tcpdump on is nice for the few situations that cal=
l for it, pf is always extremely handy, re-distributing to/from ospfd is tr=
ivial (also in OpenBSD base).
As long as you can find hardware with memory enough to scale to your number=
of routes, it's been a perfectly valid and sound option for us.
My 5 cents.
-----Original Message-----
From: NANOG [mailto:nanog-bounces@nanog.org] On Behalf Of Justin Krejci
Sent: January-12-17 12:33 PM
To: NANOG =FD[nanog@nanog.org]=FD
Subject: BGP Route Reflector - Route Server, Router, etc
Nanog,
I am working on some network designs and am adding some additional routers =
to a BGP network. I'd like to build a plan of changing all of the existing =
routers over from full iBGP mesh to something more scalable (ie route refle=
ction). Fortunately, I am also going to be able to decommission some older =
routers from the network and so shrinking the existing iBGP full mesh is so=
mething I am all too happy to spend time and energy on.
For the purpose of this thread though, I am not really interested in the ro=
ute reflector vs confederation discussion.
In doing some research[1][2][3][4][5] I see a lot of discussions, config ex=
amples, etc on using route reflectors but most suggest picking a router, or=
more appropriately a set of routers, to become route reflectors within an =
ASN. I have not found many resources discussing using a non-router box as a=
route reflector (ie a device not necessarily in the forwarding path of the=
through traffic). I am thinking things like OpenBGPd and BIRD could make a=
good route reflector though they are most often discussed in the context o=
f IXPs (ie eBGP sessions).
I am wondering if people can point me in the direction to some good resourc=
e material on how to select a good BGP route reflector design. Should I jus=
t dust off some 7206VXR routers to act as route reflectors? Use a few exist=
ing live routers and just add the responsibility of being route reflectors,=
is there a performance hit? Install and run BIRD on new server hardware? B=
uy some newer purpose built routers (Cisco, Juniper, Brocade, etc) to act a=
s route reflectors and add them to the iBGP topology? GNS3 running IOS on s=
erver hardware? Something else? How many reflectors should be implemented? =
Two? Four?
What are the pros and cons of one design over another? On list or private o=
ff list replies would be great; I'd welcome real world experiences (especia=
lly any big gotchas or caveats people learned the hard way) as well as just=
links to previous discussions, PDFs, slideshows, etc. Heck even a good boo=
k suggestion that covers this topic would be appreciated.
[1] - iBGP-to-RR migration slideshow: http://meetings.ripe.net/ripe-42/pres=
entations/ripe42-eof-bgp/sld015.html
[2] - General RR design issues: http://www.netcraftsmen.com/bgp-route-refle=
ctor-design-issues/
[3] - Video intro to RR from Cisco: http://www.cisco.com/c/dam/en_us/traini=
ng-events/le31/le46/cln/qlm/CCIP/bgp/introducing-route-reflectors-2/player.=
html
[4] - Quagga and BIRD as RR example: https://bsdrp.net/documentation/exampl=
es/bgp_route_reflector_and_confederation_using_quagga_and_bird
[5] - Countless hours on youtube: https://www.youtube.com/results?search_qu=
ery=3Dbgp+route+reflector
Lots more data is out there of course as that is part of my problem.
Thanks!
Justin
