Link to home
Start Free TrialLog in
Avatar of acinphilly
acinphilly

asked on

Dns And DHCP failover

We have 30 branches in our organization and they each have their one server for DNS and DHCP. They are all on their own sub-net.  About 90% are Citrix Zero Clients.   I am looking for an option to provide fail over in case one of these servers would go down and the wire is still  up.  I would assume you can do something with DHCP scopes and Reverse DNS but not 100%.  We are looking to a product to do this now but its going to be around 30k which is a big pill to swallow.  Please help me find some alternative options!!  Thanks
Avatar of Papertrip
Papertrip
Flag of United States of America image

What server-side software are you using for DNS and DHCP?  Which OS?
Avatar of acinphilly
acinphilly

ASKER

Its a mix of Server 2k3 and 2k8 a DC in each branch.  We are going to bring them all up to 2k8 in the future.
Ah well in that case setting up a backup DC is probably the best idea, and not just for DNS and DHCP redundancy.  I don't think your branch offices will be too happy if their only DC died :)
Avatar of SysExpert
You should consider using virtuaization.

If you have 2 servers at each location, then virtualize them, and add a 2nd DC or other high availablilty, without adding additional servers.

ESXi Hypervisor is free and will run on most server hardware.

I hope this helps !
"Ah well in that case setting up a backup DC is probably the best idea, and not just for DNS and DHCP redundancy."

I have already explained this in another question but he didnt like the idea!!
And I still don't.  There is an average of 5 people in each branch so 2 servers for 5 people seems a bit silly.    The Zero clients point EVERYTHING to the server farms in in the headquarters.  So only DHCP and DNS is the main and only functionality and redundancy I need.  Adding an additional 30 servers that have to be managed and if we change any thing on the scopes is not efficient.    
Oh, so the only services you are using on the DC are DNS and DHCP?  No user accounts or group policies or mail relay or anything?

For the DNS part, just add a secondary/tertiary nameserver for hosts in each location that points to a DC at another location.

The DHCP part isn't as straight forward and would require maybe some relay agents and perhaps some routing magic, but I'm not totally sure about that whole process, don't know anyone who does DHCP between offices ;)

It really isn't silly to have 2 redundant DNS/DHCP servers in each location, even for 5 people.  Your question, and these solutions, are for if the local machine goes down and there is still a link.  What if the local DC goes down AND the network is having issues?  You can put a DNS and DHCP server onto like a $100 server and be just fine, not like we're talkin about multi-thousand's per additional server.

SPOF == bad.
No, again the zero clients point to the main server farm so everything is in the main office.  We are setting up a 3g backup for the network in case that has a problem.  We are looking into using Ip helper on to the routers so if the DHCP server goes down it will forward them to another location.  The problem is that some routers we manage and some we do not.  If the network is having problems  then it doesn't matter how many servers you have.  Never heard of a 100$ server with the Operating System.  If you know where I can get one for 100bucks with the Os I would look into it.
no clients are using the DC's?  You originally said about 90% were the zero clients centrally managed at HQ, so I assumed the other 10% were using the DC.

There are hundreds of servers for sale on eBay that are well below $100, and that are still way overkill for just DNS and DHCP servers.  Buy one, toss CentOS on it with bind and dhcpd, and you are set.
ASKER CERTIFIED SOLUTION
Avatar of kevinhsieh
kevinhsieh
Flag of United States of America image

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial