I have an NT server running as a DHCP server and a 2003 server running as a DHCP server. Both are using different scopes in the same subnet mask. Both are also separate domain controllers. I'm curious as to why I cannot lease an IP address from the 2003 DHCP server. I authenticate to it's domain, however I continue to lease IP's from the NT domain controller. Any help would be greatly appreciated.
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2 DHCP servers on one network
- Thread starter EST7745
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wdoellefeld
Technical User
It's either 2 things. The NT box responds faster or if using the same PC it continues to contact the NT box. The IP of the DHCP server is cached and it reuses it to renew.
FRCP
FRCP
bad idea to have your dhcp like that anyway
but your machine needs to be a member of the same AD domain as the 2003 DHCP server, and the 2003 dhcp serverm ust be authorized in AD
-Brandon Wilson
MCSE00/03, MCSA:Messaging, MCSA03, A+
almost got a paragraph there
but your machine needs to be a member of the same AD domain as the 2003 DHCP server, and the 2003 dhcp serverm ust be authorized in AD
-Brandon Wilson
MCSE00/03, MCSA:Messaging, MCSA03, A+
almost got a paragraph there
- Thread starter
- #4
ryanlashway
IS-IT--Management
Bad idea because your workstations will hit which ever DHCP server it finds first, and obtain its IP, no matter what the scope is.
What are you trying to accomplish by using two different DHCP servers and scopes. I use this setup but have two different locations, my workstations must recieve IP before my switch will allow them to pass to the main DC.
Do you have two locations or are they in the same location ?
What are you trying to accomplish by using two different DHCP servers and scopes. I use this setup but have two different locations, my workstations must recieve IP before my switch will allow them to pass to the main DC.
Do you have two locations or are they in the same location ?
- Thread starter
- #6
ryanlashway
IS-IT--Management
I have this same setup. Once you move the location you will be fine.
Establish a trust between the two servers and share you AD off using the Global Catologing, create your scopes and run with it. Your switch will prevent this from happening once you are off site.
Establish a trust between the two servers and share you AD off using the Global Catologing, create your scopes and run with it. Your switch will prevent this from happening once you are off site.
oh ok i gotcha...in that case you should be fine...just disable the capability of your route to pass dhcp requests if applicable so you dont accidently get the wrong ip
-Brandon Wilson
MCSE00/03, MCSA:Messaging, MCSA03, A+
almost got a paragraph there
-Brandon Wilson
MCSE00/03, MCSA:Messaging, MCSA03, A+
almost got a paragraph there
alliknowisnetworking
IS-IT--Management
ryanlashway is right. those dhcps dont give a flying f**k, it does what its suppose to do, if it gets a request its gonna serve out an address no matter what.
I would set those two servers on diff vlans and set rules on the vlan so that dhcp servers can only serve to that vlan.
Thats what we have. two forests on two separate vlans with a dhcp on one side,and dhcp on the other.
"Users are like Prostitutes,..They need guidance"-Myself
A+,Network+,MCP+2000
I would set those two servers on diff vlans and set rules on the vlan so that dhcp servers can only serve to that vlan.
Thats what we have. two forests on two separate vlans with a dhcp on one side,and dhcp on the other.
"Users are like Prostitutes,..They need guidance"-Myself
A+,Network+,MCP+2000
It has al to do with the way DHCP is working.
If a pc is switched on it might need an IP addres so it shouts around at OSI Layer 2 (that's at the MAC address level) with a DHCPDISCOVER if there's a DHCP server around.
To keep it short.
The next step is a DHCPOFFER from the DHCP servers.
One offer is chosen by the pc and the pc sends a DHPCREQUEST message to the selected DHCP that it's offer is accepted.
Server sends a DHCPACK and the IP address is assigned.
Not much to do with AD to my opinion?
As mentioned in a previous response, to prevent problems the servers need to become isolated at layer 2. This can be done with a router and/or VLANs.
If a pc is switched on it might need an IP addres so it shouts around at OSI Layer 2 (that's at the MAC address level) with a DHCPDISCOVER if there's a DHCP server around.
To keep it short.
The next step is a DHCPOFFER from the DHCP servers.
One offer is chosen by the pc and the pc sends a DHPCREQUEST message to the selected DHCP that it's offer is accepted.
Server sends a DHCPACK and the IP address is assigned.
Not much to do with AD to my opinion?
As mentioned in a previous response, to prevent problems the servers need to become isolated at layer 2. This can be done with a router and/or VLANs.
A common VLAN configuration is to have a server VLAN and then "user" VLANs. In this configuration, the "user" VLANs would be configured with a DHCP Pointer to point the VLAN to a specific IP address(es) to service DHCP - this would obviously be your DHCP server(s).
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