Simple? Networking question

themagicone

I've seen this done, even worked on it. Just don't understand how it is set up. Let say you have 3 sites - A, B, C. All are connected to a DC via MPLS. Each site gets it own subnet so 10.1.A.0/24 B.0, C.0. The only DHCP server is at the DC and all address are handed out via MPLS. So I know the DHCP server will have a scope for each site. But, how does each site forward the DHCP requests? Would you put the DC on 10.1.X.0/21 (.1.0 - .7.0) to be in the same subnet as all sites? I worked on a project with Regis Salons where every single site got dhcp from HQ so just really curious how that all works.

Rakurai

DHCP Relay would be my answer. INE CCNA DHCP video covered it a little, which is about how much I know about it. It will have the router take the DHCP Discover broadcast and turn it into a unicast packet and forward it to the DHCP server, even if it is on a remote site, as long as it has connectivity to it. It is setup in cisco routers with the ip helper-address ip address command. Haven't had time to do any labs with this in GNS3, but they do it in the video if you want to see it in action. And since INE's CCNA videos are still streaming free it would be easy to access the videos.

jamesp1983

DHCP - Configuring the Cisco IOS DHCP Relay Agent  [Support] - Cisco Systems

Basically, use that command and create dhcp scopes on your dhcp server that will serve the various subnets.

themagicone

Thanks. I knew it had to do something with that. Always learning!