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DHCP relay


I have a server with a DHCP-server running and a DHCP scope.

The server is on another location but we need the DHCP here. We have a cisco 828 router and I activated smart relay and dhcp relay information trust all. Also i have put in the command: ip dhcp-server dhcp server)

Did i configure the router correctly? Cause workstations dont get a dhcp number on this location.

i putted an attachment in this message(twice the same file..oops), so if you dont completely understand my network, take a look at that, hope it works. I really need your help!

one router on this location has the ip:, the other one has


ip dhcp smart-relay

ip dhcp relay information option

ip dhcp relay information trust-all


ip cef

ip dhcp-server



If you are running a external dhcp server the only config you need on the router is to put ip-helper addresses on the interfaces you need to have dhcp on .

Ok I've putted an ip-helper address on my router on interface eth0. With the ip:

Thats the ip adress of the server that is running dhcp but it's located at another location, and it has to pass 2 cisco routers in order to come to the workstations who need DHCP. I've only configured the router that is connected to the workstations. Or do I need to configure the other router as well?

You were talking about ip i need to put in more then one ip addres?

Nope you just need to configure the router interface you want the addresses supplied for , it changes the broadcast into a unicast and will forward the dhcp request to the remote dhcp server .

if your'e having big problems have you considered using the router at the site as your DHCP server? i am using this at one site (been trialling it for few weeks now) without any problems, as we are wanting to centralise file and print services which is the next step. It's very simple to implement and similar to microsoft you can set the ip range/dns server/wins server etc.

just a thought.


Thnx for your reply's!

Im still testing the DHCP but im pretty sure that with your help i can make it work.

Still a little question. The helper address is enabled, so can i disable the DHCP settings on my ethernet interface?

And Pete, we can also use a server on the side where i want DHCP, or the router.

But all the locations belong to one company, and they want to use one DHCP server, management of this network is easier that way..i guess.

Thnx anyway

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