[plug] Uninterupted service network

[Justin Hall]

Could you use 'round robin' DNS table? DNS hands out an IP from a pool of 
addresses for a HOST name... then only 1 of n addresses would have a problem 
if a router goes down... (so with 2 servers half of accesses would get the 
bad server?)
but that is not quite good enough..

what about you have the 'magic' ip address that the services should respond to 
XXX.
Primary has addresss YYY and an Alias to XXX, a secondary server has another 
address ZZZ.
The secondary monitors the state of the primary server (through XXX ip 
address)... primary goes down.. secondary puts up an address alias of XXX...
Primary comes back up with only the address YYY - sees that XXX is active on 
the secondary.. so it now monitors the secondary.. the secondary goes down.. 
it alias' the XXX address - when the secondary comes up it ....
oh you may need aliases on both interfaces.. as it is the router ;)

Is that thinking sound or useful? Or am i out of my tree?

Justin 
On Sat, 12 Oct 2002 11:54 am, Jeff Williams wrote:
> I was wanting to setup up a network where:
>
> All of the servers (www, mail, sql) and their backups are machines on a
> 192.168.0.* network.
> All of the DNS entries for the servers point to the outside address of
> the router for the 192.168.0.* network, and the router
> uses NAT to send the data to the appropriate server.
> In the event of a server down the router routes data to the backup
> server, util the master comes back up again.
>
> Now, I don't have a problem with setting up the above, but I what
> happens if the router dies? I was wanting any failures to be covered
> without manual intervention, but I can't think how you can go to a
> backup router. Is there a solution, or am I heading in the wrong direction?
>
> JEff