Topic: DHCP Questions

[grattman]

All,

I ask this because I love SME, yet I am unsure how to deal with this problem. When setting up an SME installation, it asks you for a range of IP addresses for DHCP to use. My organization will be going to a WAN and this move will require me to open more IP ranges. For instance, one building now has 300+ computers. I figured it would be most efficient to set all the computers to DHCP, this would make my life easier while I developed a new organizational schema. I would set up the following:192.168.0.0 through 192.168.3.0. using roughly the first 50-60 ip addresses for static infrastructure use.

So my question to the gurus is, how, if at all, can you increase the DHCP range to include several blocks of addresses?

Thanks in advance,
grattman

[raem]

grattman

how....can you increase the DHCP range to include several blocks of addresses?

Please read the manual

http://wiki.contribs.org/SME_Server:Documentation:Administration_Manual:Chapter11

Local Networks
Some advanced users may wish to extend privileges to more than one network of computers. If you would like your server to identify one or more additional networks for those privileges, you will be asked to enter those network IDs and the subnet mask for each network here.

[william_syd]

--snip--

So my question to the gurus is, how, if at all, can you increase the DHCP range to include several blocks of addresses?

--snip--

Hmmm

From a DHCP FAQ...

# How does DHCP and BOOTP handle multiple subnets?

For the situations where there is more than one LAN, each with its own subnet number, there are two ways. First of all, you can set up a seperate server on each subnet. Secondly, a feature of some routers known as "BOOTP forwarding" to forward DHCP or BOOTP requests to a server on another subnet and to forward the replies back to the client. The part of such a router (or server acting as a router) that does this is called a "BOOTP forwarding agent". Typically you have to enable it on the interface to the subnet to be served and have to configure it with the IP address of the DHCP or BOOTP server. On a Cisco router, the address is known as the "UDP Helper Address".

http://www.dhcp-handbook.com/dhcp_faq.html#hddhs

I'm no guru and I don't have a answer.

[grattman]

Thanks for the input...

Ray/William..I have added additional subnets, and I guess where I am confused was that I didn't realize I needed to add a server for each of those to handle the larger DHCP pool. Ma I wrong in my interpretation?

If this is the case then they could be run in server only mode since they wouldn't be acting as anything other than a DHCP server.

Thanks,
grattman

[CharlieBrady]

Ray/William..I have added additional subnets, and I guess where I am confused was that I didn't realize I needed to add a server for each of those to handle the larger DHCP pool.

That's the easier way to do it. Another way would be to use routers which have a DHCP relay agent, and modify SME server to include DHCP support for multiple subnets.

If this is the case then they could be run in server only mode since they wouldn't be acting as anything other than a DHCP server.

I would never run SME server just as a DHCP server. A SOHO router could be configured to route and act as a DHCP server for a subnet, and that would be cheaper and use less power.

But the easiest way of all to support > 300 DHCP clients from a single server is to use a subnet of, say, 255.255.0.0. Find yourself a good tutorial on IP addressing and subnet masks, and you'll work it out.

[grattman]

Charlie,

Thanks for your input. I was trying to get out of this easy, but it looks like I am going to have to reconfigure over 450+ computers at two locations in a 2.5 month time frame.

Now let me run one more thing by you. It is possible to do this by adding additional boxes to act as DHCP servers? Power consumption is not a real big issue, half the lights are on in the school every night. Do theDHCP boxes need to be at all robust since all they will be doing is handing out IP addresses? I could in theory place one in each of the 3 IDFs and have it just be a 1-2 year old Dell I have laying around. Would that work?