building a DNS system

[Dave Henderson]

Vincent,
  
      If your primary server is currently serving BIND,  email, and apache (www), you could do this with two servers.  Just  configure roundrobin in DNS for the same record (ie www) so that it has  two server addresses.  Then if the primary can't be reached, a  client with automatically be directed to the secondary www server (via  DNS).  You will have to sync all the daemon data - BIND is  builtin.  You could use rsync for apache and email probably.
  
  Dave
  
  
vincentbruno at free.fr wrote:  Hi,

Actually I am using a DNS server which activities are:
- handling about 3000 domains as master nameserver
- processing mail forwarding
- performing some HTTP queries (like web forwarding)

I want building a dedicated secondary server with the same
functionality if the first one is down.

Primary server: Fedora FC3, Bind 9.5.2
Secondary serveur: Fedora FC3, Bind 9.5.2
A domain name: mydomain.com with the two nameservers above.

Processing mail forwarding is easy, the domain name is defined with two
MX records (the first nameserver and the secondary nameserver) but
about web forwarding...

I define my zonefile on both nameservers :

$TTL    3H
@               IN              SOA     PRIMARY_SERVEUR. MAIL. (
                        2006071416; Serial
                        3H          ; Refresh
                        2H          ; Retry
                        1W          ; Expire
                        1D )      ; Minimum
        IN NS       PRIMARY_SERVEUR.
        IN NS       SECONDARY_SERVEUR.
        IN MX 0    PRIMARY_SERVEUR.
        IN MX 10  SECONDARY_SERVEUR.
        IN A         IP_OF_PRIMARY_SERVEUR
www IN A         IP_OF_PRIMARY_SERVEUR

If the primary server is totally down:
DNS will be handled by the secondary NS -> OK
Mail will be handled by the secondary MX = secondary NS -> OK
http will be handled by IP_OF_PRIMARY_SERVEUR which is down -> no web
forwarding available.

What is the solution ?
Do I need a third server which will process http queries and each A
record points to its IP, but if this server is down ?
Can I use only two servers ? if yes, how ?

Thanks for your replies !!! :)