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New Member

3500XL forwarding DHCP Requests

I have a 3500 XL cisco switch. I want to be able to plug a client into a port and forward the dhcp requests to a computer I have set up running as a DHCP server. I know I really need a router, but I wanted to see if this was possible. I might also be able to set up a trunk, but then would ALL traffic go out the port the DHCP server is on? I don't think a switch is meant to handle any of this, but I thought I would check with the experts.

Thanks,

JT

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Accepted Solutions
Cisco Employee

Re: 3500XL forwarding DHCP Requests

JT,

You're right. You need a routing device (eg, 3550) to be able to fwd dhcp requests for multiple vlans. For your 3500xl you need to have clients in same vlan as the dhcp server or have a port in the vlan connected to a router. Still only possible for one vlan as you already mentioned.

5 REPLIES
Cisco Employee

Re: 3500XL forwarding DHCP Requests

JT,

You're right. You need a routing device (eg, 3550) to be able to fwd dhcp requests for multiple vlans. For your 3500xl you need to have clients in same vlan as the dhcp server or have a port in the vlan connected to a router. Still only possible for one vlan as you already mentioned.

New Member

Re: 3500XL forwarding DHCP Requests

Thanks,

JT

New Member

Re: 3500XL forwarding DHCP Requests

Hi,

It will only work if the client and server are on the same vlan. If on different vlans, you will need a router to act as a DHCP relay agent and forward the UDB broadcast to the server.

-Robert

New Member

Re: 3500XL forwarding DHCP Requests

Robho,

That is what I thought.

Thanks,

JT

Re: 3500XL forwarding DHCP Requests

You could still use a microsoft dhcp relay agent, instead of having a layer 3 device.

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