DUAL DHCP SERVERS

[speedingwolf]

What are the best ways to setup 2 DHCP servers in the same network? We have 2 AD DC and only one DHCP server. I'm curious if DHCP server has the ability to hand out IP addresses automatically just like clustering services.

Thanks

 

[GlenJohnson]

You only want multiple dhcp servers if you have more than one scope. What are you trying to do? Good luck.

Glen A. Johnson
If you're from Northern Illinois/Southern Wisconsin check out Tek-Tips in Chicago, Illinois Forum.

TTinChicago

 

[speedingwolf]

Hi,

I try to make it a redundant DHCP server. Say, if the first DHCP server crashed, i would like to see the second one start handling out IP addresses automatically. I guess it does not work that way.

Thanks

 

[doomhamur]

actually, you can have more than one dhcp server.

lets say you use 192.168.1.0 as your scope.

one server would use 192.168.1.1-128 for the scope, the other would use 192.168.1.129-254.

As long as you set the dns servers, default router information the same on both dhcp servers

This way your machines would get an ip address from either server, if one went down the other would still hand them out.

you could also use two different ranges:
192.168.1.1-254 on one server
192.168.1.2-254 on another

it just depends on how you subnet your network.

Doomhamur
Network Engineer
"Certifications? we dont need no stinking certifiaction."
yahoo IM handle: greater_vortex

 

[speedingwolf]

Wow! Thanks Doomhamur. Let me me try to setup that scenario this weekend and see if that will solve my problem.

Thanks all.

 

[doomhamur]

no problem, i am suprised that glen did not offer this solution, excetp he likes to know the reason you want to do things.

Doomhamur
Network Engineer
"Certifications? we dont need no stinking certifiaction."
yahoo IM handle: greater_vortex

 

[jtb]

To provide for uninterrupted operation of the network, it's worthwhile to consider implementing more than one DHCP server for a given segment. Doing so prevents a problem from occurring if an IP address lease expires at a device and isn't able to renew.

The trick to using more than one DHCP server for a given segment is that an address given out by one DHCP server can't be given out by another DHCP server. If this dual assignment of an address were to happen, and more than one device were to claim the same IP address, think of the problems that would occur when routers started getting confused as to where a particular package should be routed.

When you create redundant DHCP scopes (Microsoft terminology for more than one DHCP server), you'll need to enable bootp forwarding on a given segment so that if the local DHCP server can't respond, the request for address assignment can be forwarded to the DHCP server that can answer the request.

http://www.microsoft.com/technet/pr...s/techrep/tcpimp.mspx#XSLTsection125121120120

Also see:

http://www.microsoft.com/technet/prodtechnol/winntas/support/sur_dhcp.mspx

Microsoft Knowledge Base Article - 301187
HOW TO: Install and Configure a DHCP Server in a Workgroup in Windows 2000

http://support.microsoft.com/default.aspx?scid=kb;en-us;301187&sd=tech

Microsoft Knowledge Base Article - 300429
HOW TO: Install and Configure a DHCP Server in an Active Directory Domain in Windows 2000

http://support.microsoft.com/default.aspx?scid=kb;en-us;300429&sd=tech

JTB
Have Certs, Will Travel
"A knight without armour in a [cyber] land."

 

[speedingwolf]

You guys rock! Enough said!

 

[GlenJohnson]

no problem, i am suprised that glen did not offer this solution, excetp he likes to know the reason you want to do things
Quite right. You'd be surprised how many people are trying to do x, but they ask about y. I also like having a clear picture before offering advice. Thanks for the help.

Glen A. Johnson
If you're from Northern Illinois/Southern Wisconsin check out Tek-Tips in Chicago, Illinois Forum.

TTinChicago

 

[GlenJohnson]

You can also check out

http://www.microsoft.com/windows200...net/cncb_dhc_ogjw.asp?frame=true&hidetoc=true

Glen A. Johnson
If you're from Northern Illinois/Southern Wisconsin check out Tek-Tips in Chicago, Illinois Forum.

TTinChicago