Home page logo

nanog logo nanog mailing list archives

Re: Disaster recovery using as-prepend?
From: "Ejay Hire" <ejay.hire () isdn net>
Date: Thu, 16 Feb 2006 12:00:34 -0600


Answering the original question, as prepends are not a definitive way to force all traffic to one site or the other.

Two ways that definitely will work are.

1. Send a community to the upstream provider at the backup site that causes them to set a lower plocalpref on the route you send them vs. the route learned from the internet.

2. If you have a large enough ip block, Advertise an aggregate address from your backup site, and more specifics from your primary. I.e. advertise a /23 from your backup site and the same /23 as two /24's from the primary.


Thu, 16 Feb 2006 16:10:02 +0100
 Florian Weimer <fw () deneb enyo de> wrote:

* Christopher J. Pilkington:

We have a disaster recovery site which will have a clone of the myriad
production servers.  We'd like to fail over to that site

I'm thinking advertising the same prefix and just doing several as-prepends. However, now I'm not sure if this is a polite thing to
do or not.

Can your backup servers run in parallel to your primary servers? How do you handle conflicting updates (assuming that the services are not
completely stateless)?

  By Date           By Thread  

Current thread:
[ Nmap | Sec Tools | Mailing Lists | Site News | About/Contact | Advertising | Privacy ]