DHCP forwarding

stoneystone · ‎09-01-2009

I have an issue I need to solve.

Here's my network:

dhcp server > Catalyst 2950 > Catalyst 4506e > ASA 5510 > 2811 Router > Internet

What I have is a guest network, for general guest(192.168.x.x.), and the ASA is handing out ip addresses.

Internal network is 10.x.x.x

What I need is to have the ASA continue handing out IP addresses to the network (192.168.x.x) and:

1. have two new networks - on the PIX 10.1.2.x and 10.1.3.x

2. have these two new network receiving dhcp addresses from a server on the internal network - 10.1.4.x - an existing network.

Is this possible with the equipment I have? If so, I need some good info on how to set it up.

Thanks, and any help would be greatly appreciated.

Yudong Wu · ‎09-01-2009

You need enable dhcp relay on the related the gateway device for those subnets.

For IOS router/Layer 3 switch, you can just add "ip helper-address" command under the related layer3 interfaces.

For ASA/PIX, you can use dhcprelay command

http://www.cisco.com/en/US/docs/security/asa/asa80/command/reference/d2.html#wp1906722

But you can not specify the different dhcp server IP for different interface on ASA.

Therefore, the solution will depend on how network 10.1.2.x, 10.1.3.x and 192.168.x.x are connected to your network and which device is their default gateway.