backup connection for my domain

[nelu]

Hello

I have a domain and two providers (2 different ip's)
What i want to do is to set my server in such way that when a connection fails my www domain can be accesed on the other provider.
I think the steps are:
- set the dns at the registrar so it will point (in some way) to both ip's
- configure bind
- maybe also configure apache
- and configure the routing in linux

Any ideea how to actually do this?

Thanks.

[secondmouse]

Adding an additional A record for the www.whateverdomain.name to the bind zone file should be enough. Check out Round Robin DNS Load Balancing - WebsiteGear for detail [ section titled "DNS load balancing implementation (Multiple A Records)" ]

[Lazydog]

While adding a second record to DNS will allow both ISP's to be used there is a down side. The down side is that when one of the routes goes away there is no way for DNS to know this and it will still give out the downed IP address. Thus half of all connections will fail.

The only way I can think this will work is some sort of Dynamic DNS entries with a script that watches both connection and removes the down record from DNS.

The problem here is the TTL of your records. Once a record is cached it is held until the TTL is reached then discarded. If this record is given out and then 1 second later the link goes down the cached record will be used until it expires.

The best option would be a load balancer. It will know about both IP's and when one goes away it will direct all connection to the live one. While both are present it will use both IP'S.