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New Member

dhcp relaying???

I have 2 networks joined by a T1 with a 1720 on each end of it. I use a W2K server for dhcp and have 2 zones created for each network. One is 10.10.10.x/ and the other is 10.10.20.x/ I can't get the .20 network to use dhcp. I have dhcp enabled on the clients and i have fumbled around with some iphelper addresses with no avail. My dns/dhcp server is Any help would be great....

New Member

Re: dhcp relaying???

Lets say you have router A with the remote clients and router B with the local clients and DHCP server. You must have the command "ip helper-address" issued on the interface that connects the router A clients (interface fastethernet0 or whatever). This will make the dhcp broadcast request a unicast to the DHCP server. Ensure you dont have NAT running between the two subnets because the DHCP server will used the proxied DHCP requesting routers address to pull from the appropriate pool. Check your DHCP pool for accuracy as well. As an alternative you can setup the 1720 as a DHCP server as well.

ip dhcp pool test


dns-server X.X.X.X

netbios-name-server X.X.X.X

netbios-node-type h-node



lease 10 <--- Ten days lease length


Re: dhcp relaying???

This worked like a charm. Thing is now i can't ping from B to A or remote control workstations with VNC. Any ideas on this?

New Member

Re: dhcp relaying???

Check the default route you are passing the clients via DHCP that it is their router address. post your config if this is correct and I will take a look.

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