Re: Euro-IX quagga stable download and implementation

[Andy Davidson <andy () nosignal org>]

Hi, Goran, everyone --

On 23 Apr 2015, at 09:06, Goran Slavic <gslavic () sox rs> wrote:

> at the mailing list and have an interest in downloading and implementing the Euro-IX version of Quagga in our 
> Internet exchange. My questions are simple:
> - Considering the time when the post is written (2012) - what is the current status of the Euro-IX Quagga ?
> - Where can it be downloaded as a stable release / version ?

This email is a comment on using this software as a route-server, and not a comment on using this software as a RIB 
manager on a forwarding device - if you’re a reader from the future trying to understand about running this software on 
a router, then please bear this in mind.

There are three well known open source BGP implementations which are commonly used as a route-server - BIRD, Quagga, 
and OpenBGPd.  It is typical to configure them today in a way that has the route-server calculate a different RIB for 
every connected ASN on your exchange.  This is because it is also common to allow route-server users to filter (prevent 
their prefixes reaching) other participants.  Information about why this is important has been published in various 
presentations and papers at IX and operator events.

Calculating best-path for every participant becomes complex when you have a lot of participants, further when the 
number of prefixes on the exchange grows.  

OpenBGPd will stay up but take a very long time to process and forward announce/withdraw BGP messages.  On a ~100 
ASN/participant/table system with ~5000 prefixes, it can take anywhere up to an hour for a withdraw to be processed and 
forwarded which means your participants will get a route that is withdrawn for a long time and blackhole traffic at the 
exchange. It is therefore problematic to use this software on all but the smallest exchanges.  It’s OK on small 
instances but does not scale.

Quagga’s vanilla build will fail to stay up with large numbers of tables and participants.  Chris Hall did an amazing 
job at making a build that was more prone to staying up and his build is doing a sterling job at LINX (alongside BIRD) 
but I understand that this source tree is no longer maintained and that the task of merging his stability fixes into 
the mainline or OSR (https://www.opensourcerouting.org) version is not a simple job and has not been done.  This gives 
me a serious concern about the future of this branch.

BIRD just doesn’t die, no matter what scale we seem to throw at it.  This thing just keeps flying.

We now have two (busy) BIRD instances at the LONAP exchange in London where most of our 150 exchange point members use 
the service.

Goran - SOX is a member of the Euro-IX association for exchange points and there is a private mailing list for members 
who operate route-servers.  There may be a greater concentration of route-server operators on that list so it’s 
probably worth continuing the discussion there?  You sign in to the website and visit 
https://www.euro-ix.net/mailing-list-archives to subscribe.

With best wishes,
Andy Davidson
(Relevant Hats: LONAP, IXLeeds, Euro-IX, IIX, NapAfrica)