Thanks for your response. I understand the theory of DHCP but the practical implementation is defeating me! In theory the scope I have is now wide enough to cope with lots of devices but I still don't have a DHCP server that can manage it. The only machine that is on the network is a Windows 7 PC. This remains on all the time and is rarely rebooted. I could use that as a DHCP server I guess but is there a program that can do it? I've had a search around but none of them look really impressive! Have you any recommendations? I'm assuming the DIR-615 could handle this, I'll have a look at that too.

Hi,

yes, that Windows 7 machine may work.
You will need to configure it with a static IP address, and install a 3rd party utility like http://sourceforge.net/projects/dhcpserver/

Assuming you configure your network as 10.0.0.0/16 (255.255.0.0), you could use
10.0.0.1 - 10.0.0.255 for static addressing
10.0.1.0 - 10.0.1.255 as DHCP assigned by the Draytek (so there is always a DHCP server)
10.0.2.1 - 10.0.255.254 as DHCP assigned by the Windows 7 machine.

That should give you about 65278 addresses that can be assigned via DHCP, should think that'll do unless you have a VERY large hotel

Thanks, that's really helpful. I'll download the DHCP server and try it in a 'play' area before letting loose in the real world.

Some questions, can you have two DHCP servers on the same network? I guess it's OK if they are dealing with different networks.

If a PC comes up and gets it's IP address from W7 machine what gateway would it use? If it's IP address is 10.0.2.12 would it be able to get to the gateway on 10.0.0.1? I guess with a subnet of 255.0.0.0 or 255.255.0.0 there shouldn't be a problem as they would all effectively be on the same network.

I'll definitely give this a go!

Hi Neil,

the default gateway is one of the things you specify as a parameter of the DHCP lease. It should be the same whichever DHCP server the lease is assigned from - presumably the address of your Draytek (10.0.0.1).

Yes, you can have multiple DHCP servers. In fact, it is common to have Windows Server acting as DCHP server in Active Directory environment. By default, two Windows DHCP servers cannot act as failover to each other, so most commonly, you would have two servers that assign different ranges. It's not easy to control which server a lease comes from (it'll use whichever responds first), but that doesn't usually matter.
Once the lease is assigned, the DHCP server will do nothing until the lease is up for renewal, so even if the server goes down, the client will be able to continue to work normally.

Correctly observed, with a subnet mask of 255.255.0.0 the x in 10.0.x.x are all in the same subnet, and clients in the same subnet can talk to each other (and have the same gateway).

Has this been resolved does anyone know, I am specking one of these for a busy campsite and really don't want to mess around with another box to handle the DHCP server.

Nope, still a limit of 256 address in the DHCP pool on 3.7.8, 2860n