BGP Anywhere - Global Redundancy

Thu Apr 7 10:21:45 UTC 2005

There are New IOS features for such situations, take a look at
datacenter backup, SLB and these issues.

On Apr 7, 2005 2:35 AM, Vandy Hamidi <vandy.hamidi at markettools.com> wrote:
> 
> All,
> We're an ASP and are considering adding a secondary Backup Datacenter
> (BDC) in the US to protect our web presence.
> 
> My goal is to ensure automatic failover of my Primary DC's (IP) traffic
> to the BDC in the event of a catastrophic failure of the PDC.
> 
> I'm considering geographic load balancing and BGP Anywhere as the two
> options.  I'm clear on how the Geo LB works, but have some doubts about
> BGPAW as I've never implemented it before and documentation online is
> pretty weak to non-existent.
> 
> Below is how I believe it should be done.
> From PDC:
>         -Advertise CIDR block to all peers w/good metric (0 hop count)
> From BDC:
>         -Advertise same CIDR block to all peers w/poor metric (+20 hop
> count)
> 
> During normal operation, all ASes will route production traffic to PDC.
> In the event of catastrophic failure at PDC; PDC advertisements will
> cease, BDC route will become the only one on the net and traffic will
> route to the BDC.
> 
> Questions:
> 1) Will this work?
> 2) Other suggestions or alternatives?
> 3) Any chance that traffic could flow to BDC for any reason?
> 4) Any internet etiquette I could be ignoring?
> 5) What would you estimate the failover time would be?
> 6) Assuming the routers at PDC and BDC pull down full routing table, how
> will the receipt of the PDC CIDR advertisement be treated?  BGP rules
> say it will be dropped as a routing loop.  What alternatives would I
> have if I want to be able to route that CIDR block traffic from the BDC
> to the PDC.  Confed?  Cisco conditional advertisements?
> 
> Thanks all.  This is the only place I can think of that would have the
> expertise to comment.
> 
>         -=Vandy=-
> 
>