[c-nsp] Anycast//DNS - BGP

[adam vitkovsky]

Hi Henry,

Please note that even though the diverse-path RR feature is easy to deploy
there's one possible drawback to be taken into consideration
Once configured with the diverse-path feature the RR will start to advertise
all paths for all prefixes to all its clients -so you should make sure all
the RR clients can cope with the tables growth (depending on the # of
prefixes and the # of alternate paths per each prefix) -please note that
this will affect all the bgp speakers not just those clients that really
need the diverse paths for loadsharing or anycasting purposes 

If you are using mpls in your backbone you'd definitely want to be using
different RD per each bgp speaker to make the prefix unique from RR's
perspective

Matthias,
What I've used for anycast or multipath in pure IP bgp-RR environments prior
to the diverse-path or add-path features was adding the Path-Based-RR to the
existing AddressBased-RR or Topology-Bassed-RR 
So for 6 paths you'd have 6 RRs each choosing the same prefix with different
path as best passing it down to all clients -and have clients to peer with
all 6 RRs
Please note these where pure control plane RRs
As you can see this doesn't scale well as the separate RR infrastructure
needs to be built for each diverse path that needs to be propagated to RR
clients


adam

-----Original Message-----
From: cisco-nsp-bounces at puck.nether.net
[mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Robert Raszuk
Sent: Friday, May 04, 2012 5:48 PM
To: henrry huaman
Cc: cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] Anycast//DNS - BGP

Hi Henry,

 > Currently we have issues with the RR (Only select the main route)

That's an easy one to solve :)

Try using either add-paths or diverse-path on the RR. The latter is much
easier as it does not require upgrade of all of your BGP speakers !

http://goo.gl/KDjlg

Best,
R.

> We want to work with DNS that are span geographical. Our DNS have the same
IP.
> We need to configure the Backbone IP (BGP) to distribute this IP
(Anycast).
> Could you have any examples over how to deployment Anycast?
> Currently we have issues with the RR (Only select the main route)
>
> Thanks a lot!
>
> Henry
> _______________________________________________
> cisco-nsp mailing list  cisco-nsp at puck.nether.net 
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/
>
>

_______________________________________________
cisco-nsp mailing list  cisco-nsp at puck.nether.net
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/