DHCP For Remote Sites?

Question

I was assigned to make a connection between two sites (A & B) with 512kbps dedicated lease line. Site A (2 DCs) and Site B (1 DC) integrated with Sites and Services configurations. Site A is at 192.168.0.x whereas Site B is at 192.168.3.x. DHCP server is at Site A's DC2. My question is how do I configure the DHCP Server so that the clients in Site B can obtain 192.168.3.x instead of 192.168.0.x? DHCP Superscope? How do I configure both end of the lease line routers? Should I configure the relay agent on the routers? Please advise. Thank you in advance.

Thank you guys for your reply.

For GTB, your answer to me is too deep before I clarify my confuse part as below:

For Necros, I think you got my "confusing part". Let me explain further, hope you guys can help me on that. Actually I am newbie in setting up windows server.

At now, my Site A is running smoothly with 2 DC replicating each other. My plan is to integrate another DC from Site B by using sites replication. The problem is will I still see Site B's DC pointing to the same DHCP server with 192.168.0.x range? I am confusing at this part. Because from what I see from my Site A, DC1 and DC2 is sharing the DHCP range. I afraid if I replicate DC3 from Site B, it shares the same range too! This will be a big problem for me, all my clients in Site B will obtain 192.168.0.x and not 192.168.3.x

Any good advice?

Answer 1

You *can* install a DHCP relay for site B, But why ?
If you've got a DC on site B, Install DHCP Services onto it and have DHCP take care of at the local level.
AD / DNS will update the info between the sites so finding individual PC's shouldn't be a problem.
Plus you can concentrate on controling the replication traffic and maximizing throughput instead of having constant DHCP overhead.

Answer 2

Let's recap

Site A uses subnet 192.168.0.0/24 in its LAN. I am assuming a 24 bit subnet (255.255.255.0 in this application at both sites.)

Site B uses subnet 192.168.3.0/24 in its LAN.

There is a Point - Point T1 between A and B, actually a Fractional T1, 8 chanel at 512 Kbps between the 2 locations.

You did not mention about ANY Internet access at either location. I am going to assume there is NO internet access desired at all.

The point - point T1 is terminated with a smart jack. This requires an access router (router with a csu / dsu) not a gateway router. An Adtran Netvanta 3200 with a T1/FT1 NIM is ideal for this application. You need one at each site.

Configure the Side A access router as follows:

1. Assign the WAN port a static IP of 10.10.10.1, subnet 255.255.255.0, default gateway 10.10.10.1.
2. Provide DHCP from the access router and deactivate the existing DHCP server.
3. Configure the router's LAN port with router default gateway of 192.168.0.1, subnet 255.255.255.0; if any device now has the 192.168.0.1 IP change that device. Configure router to provide DHCP in the 192.168.0.100-255 range and leave the 192.168.0.2-99 IP pool for static devices.

For Side B:

1. Assign the WAN port a static IP of 10.10.10.2, subnet 255.255.255.0, default gateway 10.10.10.1.
2. Provide DHCP from the access router and deactivate the existing DHCP server.
3. Configure the router's LAN port with router default gateway of 192.168.3.1, subnet 255.255.255.0; if any device now has the 192.168.3.1 IP change that device. Configure router to provide DHCP in the 192.168.3.100-255 range and leave the 192.168.3.2-99 IP pool for static devices.

I suggest you set up static routing tables on the routers so the routers can direct traffic back and forth properly. There is so little routing that there is no merit using RIP, OSPF, BGP, or any other automated routing protocol, although you could use them if you wish - however with a 512 Kbps point - point I would hate to consume bandwith with an unneeded automated protocol's continual updates.

After you install the routers, reboot all downstream devices so they have new IP addresses via DHCP from the access routers and you are in operation.

Finally, if you also want Internet access on this network you only need 1 ISP access at one end to feed the entire network. In this case, you also alter the routing table to assure internet access. Depending upon the Internet service you may need an access router (if you are using the Netvanta 3200 get their dual T1 NIM which goes in the same chassis). If your internet service provides an ethernet hand off, use a gateway router for Internet, assign the LAN IP for this router with a static IP probably 102.168.x.2 where x is dependant on if it is on side A or side B (this assumes the x.2 is not in use) and configure the WAN side for either a dyanmic or static IP per your ISP's direction..