First, both web server IP Address should be reachable thru internet BGP or no BGP (no BGP if you have static route to a single ISP). This is common nowadays.
Second, your DNS zone file TTL should not be higher than 1 hour (with high end compute nowadays this should be achievable). When the HQ site is down, change the "A" record for your web address from HQ IP Address to DR IP Address. Fro example;
I agree completely. This is a DNS solution, not something for BGP. There are also some nice DNS solutions out there that will montior your website looking at the application and will automatically update DNS records in case of failure.
We have something exactly what is being discussed over here.
The easiest way to manage this is with the help of the Content Networking, and to be very specific Content Routing. Ofcourse our organization started when I guess Cisco's CSS gear were not very popular hence thus far we have been using quite effectively on F5s.
Implementing DR using the BGP for services would not turn in to a cost effective solutions as the Peering / Routing cost would boost very high!
Here is the document for configuring GSLB with DNS on a CSS. Basically, the CSS pair becomes the authoritative dns for yourdomain.com. The A records are located on the CSS's themselves. There is an app session between the 2 CSS's in which they exchange service, keepalive information etc. If the primary service is up, via a keepalive of some sort, the CSS will resolve to that VIP (A record). If the service is down, the CSS will resolve to the backup VIP. It works really fast.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.