2 dhcp server in a network

Unanswered Question
Jan 14th, 2009
User Badges:

I have a 3750 acting as a dhcp server with a range of IP pool and a linksys router with another set of pool. Is there anyway I can configure that certain workstation getting IP from 3750 and certain workstation obtaining from the linksys router?Both are running on different vlan with routing on the 3750.

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 5 (1 ratings)
Loading.
John Blakley Wed, 01/14/2009 - 07:06
User Badges:
  • Purple, 4500 points or more

Well first, you can have separate DHCP servers as long as they are on:


a) Separate subnets

b) serving different scopes


That in mind, if you have a dhcp scope on your 3750, you would need a vlan interface that is addressed in that same scope:


int vlan 50

ip address 192.168.50.1 255.255.255.0


ip dhcp pool VLAN50

network 192.168.50.0 255.255.255.0

default-router 192.168.50.1

dns-server 4.2.2.1


On the OTHER DHCP server that you want to get your addresses from, you would need a separate VLAN interface configured with an IP address like:


int VLAN 100

ip address 192.168.100.1 255.255.255.0

ip helper-address 192.168.100.50


Anything coming in on VLAN 100 will go to the 192.168.100.50 to get an address. You would need a pool for 192.168.100.0 on the DHCP server for that.


I wouldn't recommend using separate DHCP servers though because you can use just the one DHCP server (Linux/Windows) to serve multiple scopes. All VLANs in your switch would have the helper-address assigned as your one DHCP server.


int vlan 50

ip address 10.50.1.1 255.255.255.0

ip helper-address 192.168.100.50


int vlan 225

ip address 172.22.225.1 255.255.255.0

ip helper-address 192.168.100.50


int vlan 322

ip address 192.168.32.1 255.255.255.0

ip helper-address 192.168.100.50


On the DHCP server, you would have:


Scope

10.50.1.0

172.22.225.0

192.168.32.0


You would set all of your options that you need to assign under those scopes.


HTH,


John

Actions

This Discussion