multiple DNS servers in the same network?

  • Thread starter Thread starter Bill Nguyen
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Bill Nguyen

Win 2K & 2003 servers

I would like to setup additional DNS servers in the same netowrk. Is this
possible? recommendable? If so, where should I start?
Thanks
Bill
 
I would like to setup additional DNS servers in the same
netowrk. Is this possible? recommendable? If so, where
should I start?
Click to expand...

Yes, it's possible and recommendable too, first of all setup
the other DNS servers so that they'll work "barebone", next
on each new DNS create the same zones you have on your
primary (current) DNS, such zones will be created as slave
(secondary) zones, at that point your secondary servers will
automatically fetch a copy of such zones and will answer for
them; keep in mind that to change the DNS record you'll then
only need to change the _primary_ DNS since all changes
will be automatically propagated to the other DNS servers
such a config will give you an additional "fallback" mechanism
so that, if for any reason the primary DNS will fail you'll still have
the secondary ones serving data to the clients ... and btw don't
forget to configure the clients to use the other DNS servers too :-)
 
Danny & ObiWan;
I fact, I would like to try both approaches.
Since our network has both Win2K & 2003 servers, I would like to try the AD
integrated DNS first. I'm also using a RAS server that allows VPN
connection. In the RAS setup, DNS IP address is pointing to the primary
(and only) DNS server.
Now with AD integrated DNS, which ip adddresses should I enter for the RAS?
Thanks
Bill
 
In
Bill Nguyen said:
Danny & ObiWan;
I fact, I would like to try both approaches.
Since our network has both Win2K & 2003 servers, I would like to try
the AD integrated DNS first. I'm also using a RAS server that allows
VPN connection. In the RAS setup, DNS IP address is pointing to the
primary (and only) DNS server.
Now with AD integrated DNS, which ip adddresses should I enter for
the RAS? Thanks
Bill
Click to expand...


Just to add, if all your DNS servers are AD DCs, you can make the zone AD
Integrated. More advantageous to do that. For the RAS server, assuming you
mean what to give your clients when they connect, set any of the DNS
server(s) as their DNS address, as long as the servers all have the same
zone info on them.

An AD Integrated Zone 'acts' like a Primary Zone. The major difference is
that AD Integrated zones store their zone in the physical AD database and
not in a text file. If you install DNS on another DC, and then create that
same zone that's on the other DC/DNS, and then make the zone AD Integrated,
the zone data appears immediately since it pulls it from the AD database.
The advantage is no zone transfers need to be configured. Also all the
machines 'act' as the master or Primary DNS server so you can make changes
on any of them. If you like, you can create a secondary zone on another DNS
that is not a DC. But you can';t make another Primary zone since these guys
are the 'Primary' zones.

As Obi said, make sure you configure your clients with more than one DNS so
there's failover.

--
Regards,
Ace

Please direct all replies ONLY to the Microsoft public newsgroups
so all can benefit.

This posting is provided "AS-IS" with no warranties or guarantees
and confers no rights.

Ace Fekay, MCSE 2000, MCSE+I, MCSA, MCT, MVP
Microsoft Windows MVP - Active Directory

HAM AND EGGS: A day's work for a chicken;
A lifetime commitment for a pig.
 
Thanks for the tip, Ace.
Here's the situation:
Now I have 2 DNS on 2 DC's , the RAS server is one of them. The RAS is
configured to use the network's only DHCP server to generate ip addresses
for VPN clients. In the DHCP server, both DNS's addresses are used, assuming
that if 1 is down, the other would continue to provide DNS service. I may
setup another DNS on another DC to see how it work.

Can I also have multiple DHCP servers, just in case?
Thanks
Bill




"Ace Fekay [MVP]"
 
Can I also have multiple DHCP servers, just in case?

Yes, but you'll need to split the IP ranges to avoid
overlapping; just to clear up a little, let's say you
have a subnet like 192.168.100.x/255.255.255.0
and that you have a single DHCP server and a
single scope serving the whole IP range (well
excluding reservations and so on); now, to use
two DHCP servers you'll need to split the scope
in two so that DHCP_A will serve (e.g.) addresses
from 192.168.100.1 to 126 and DHCP_B will serve
the other addresses; another solution may be
using a different netmask/network class so that
you may have (e.g.) a DHCP on 10.1.1.x and
another one on 10.1.2.x both with a 255.255.0.0
netmask (or 255.255.255.240 or whatever else
will fit for you) the choice is simple, pick the
solution which will allow each DHCP server
to have enough addresses to serve _ALL_
the possible clients (since such a thing may
happen if one of the servers will be down)

Regards
 
In
Bill Nguyen said:
Thanks for the tip, Ace.
Here's the situation:
Now I have 2 DNS on 2 DC's , the RAS server is one of them. The RAS is
configured to use the network's only DHCP server to generate ip
addresses for VPN clients. In the DHCP server, both DNS's addresses
are used, assuming that if 1 is down, the other would continue to
provide DNS service. I may setup another DNS on another DC to see how
it work.

Can I also have multiple DHCP servers, just in case?
Thanks
Bill
Click to expand...

Multiple DHCP servers require for you to split th scope among them. Usually
an 80/20 will do, but for most installations that I know (major ones
included) no one really bothers with this.

Word of advise, don't run DNS on a RAS server. Problematic and may require
registry alterations to circumvent certain issues.

If you install antoher DNS elsewhere and its not on a DC, you can create a
secodnary of your current zone and specify one of your DC/DNS to be the
Master.

--
Regards,
Ace

Please direct all replies ONLY to the Microsoft public newsgroups
so all can benefit.

This posting is provided "AS-IS" with no warranties or guarantees
and confers no rights.

Ace Fekay, MCSE 2000, MCSE+I, MCSA, MCT, MVP
Microsoft Windows MVP - Active Directory

HAM AND EGGS: A day's work for a chicken;
A lifetime commitment for a pig.
 
Thanks ObiWan & Ace.

Bill
ObiWan said:
Yes, but you'll need to split the IP ranges to avoid
overlapping; just to clear up a little, let's say you
have a subnet like 192.168.100.x/255.255.255.0
and that you have a single DHCP server and a
single scope serving the whole IP range (well
excluding reservations and so on); now, to use
two DHCP servers you'll need to split the scope
in two so that DHCP_A will serve (e.g.) addresses
from 192.168.100.1 to 126 and DHCP_B will serve
the other addresses; another solution may be
using a different netmask/network class so that
you may have (e.g.) a DHCP on 10.1.1.x and
another one on 10.1.2.x both with a 255.255.0.0
netmask (or 255.255.255.240 or whatever else
will fit for you) the choice is simple, pick the
solution which will allow each DHCP server
to have enough addresses to serve _ALL_
the possible clients (since such a thing may
happen if one of the servers will be down)

Regards
Click to expand...
 
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