Active standy primary DNS

[Mad_1]

A close network is formed in my environment. There is a L3000 HP-UX 11.0 is configured as Primary DNS server.

There are some HP-UX 11.0 and HP-UX 10.20 servers are configured as Secondary DNS servers. Those Secondary DNS servers will acquire zone transfer from the single Primary DNS server when DNS update.

As I am configuring a DR server for the Primary DNS server. I would like to ask can I configure the DR server as an active standby Primary DNS server, that means when the production Primary DNS server is down, those Secondary DNS servers should know the DR server is taking the control and acquire the zone transfer from the DR server.

Is it possible and how to configure?

Thanks

[twang]

You can get BIND 8.1.2 release for HPUX11.0/11i
http://www.software.hp.com/cgi-bin/swdepot_parser.cgi/cgi/displayProductInfo.pl?productNumber=BIND812

Once you have created a master(primary) dns server, you can walk through:
1. copy named.conf file and db.cache from master(primary)
2. edit named.conf:
- change each instance of "master" to "slave", except for the lookback domain db.127.0.0 and the cache entry
- add a "master" entry for each zone with IP of master dns server
3. once copy named.boot has been copied to /etc/named.boot and your /etc/named.data dir has been created, kick off a zone transfer:
# sig_named restart
or
# kill -HUP `/var/run/named.pid`
to start the transfer.
You may now take a look at /etc/named.data and you should see all the database file there now. Check /var/adm/syslog/syslog.log to make sure that the zones were loaded properly.
Notice the serial number entries. they should match on master(primary) and slaves(secondaies).

[Mad_1]

The Primary and Secondary DNS servers have been configured well and running for a long time.

I would like to ask is that :

1. A new DR server will be configured.
2. I would like to configure this DR server as the Primary DNS DR server. Once the Primary DNS server is down, the DR server should take up the function as Primary DNS server.
3. Is it possible to configure this as active standby. That means no special configuration is required when DR. All secondary DNS servers can switch to point to the DR server.

Thanks

[Steven Gillard_2]

Service Guard is the obvious choice here - are you planning to install that? It can handle the fail-over of both the network interface and the data (on shared disks).

All you need to do is configure the master name server to listen on the "floating" address and the slaves to communicate with that address for their updates. The DR fail-over will be transparent to the slaves unless it happens while a transfer is in progress.

Regards,
Steve

[Mark Greene_1]

When your DR server become the live server, will it assume the IP address and hostname of the primary server? If, then DNS on the secondary DNS servers will continue to operate normally. They won't, for all practicle purposes, be aware of any change at all.

HTH
mark

[Steven E. Protter]

I recommend something slightly different.

You can have two primary DNS servers with the same BIND database.

Your other machines have the primary DNS as the first nameserver in /etc/resolv.conf and the secondary as the second line in /etc/resolv.conf

This setup provides redundancy that is automatic without ServcieGuard. You can still have secondary servers that connect to primary and failover can be handled with /etc/resolv.conf and /etc/nsswitch.conf configuration.

SEP

[Mad_1]

Thanks a lot for all of your reply.

As the DR server is located in a different site, therefore, MC/SG is not feasible.

I am considering the DR server will not take the hostname and IP of the production primary DNS server. Therefore, I would like to find out a way that if the DR server can be setup as a hot standy primary DNS.

As I mentioned, there are some HP-UX 11.0 and HP-UX 10.20 secondary DNS servers, therefore, I am not worry about the DNS services providing to other workstation, servers to obtain. What I am worry about is the zone transfer service from primary to secondary DNS servers.

[U.SivaKumar_2]

Hi,

Why not ?

Say you have two standalone master DNS servers.

xx.xx.xx.xx
yy.yy.yy.yy


Now you want to DR setup for all slave servers then edit named.conf in all your slave servers and put this in all your zones.

zone "mydomain.com" in {
type slave;
file "db.mydomain";
masters { xx.xx.xx.xx; yy.yy.yy.yy; };
};

reload named.

regards,

U.SivaKumar