Jeff Vincent, 2001-Dec-11 19:25 -0700: > There are no other routers between the subnets that I know of. > > When we configure our machines statically, all use the same static > route at address X.Y.D.254 (same as static route?) and all use the same > subnet mask of 255.255.252.0 regardless of subnet and has been that way > for nearly 2 years. (netmasks have always been a bit of voodoo magic > for me anyway (see question below)? ack!) However, our IS dept. told > us to use that subnet mask and additionally delegated us a domain and > the 4 class C subnets for our testing use. At least I thought they were > class C address blocks: > > X.Y.A.[0-255] > X.Y.B.[0-255] > X.Y.C.[0-255] > X.Y.D.[0-255] > > where the '0' is the network and '255' is the broadcast address.
Okay, so the the mask you are using actually makes those four blocks into a single subnet. So, you don't have for routable subnets configured, you have a single subnet of ~1000 host addresses, a single network address of X.Y.A.0 and a single broadcast address of X.Y.D.255. This is generally not a good idea for several reasons, but it's obviously functional. To make those four Class C blocks into four subnets, you'd need to change the mask to 255.255.255.0 and you'd need to do some routing. > If I change the netmask to 255.255.252.0 I get this message: > > No subnet declaration for eth0 (151.155.155.252). > Please write a subnet declaration in your dhcpd.conf file for the > network segment to which interface eth0 is attached. > exiting. > > I then added an additional subnet declaration for <subnet4> inside the > shared-network section but with no range (we don't want any of this > subnet in the dhcp pool) and now it seems to work. I am most confused. Ah! I didn't catch that the first time. Yeah, you have to declare all interfaces that the system has configured. Dhcpd checks them all and shouldn't even start the daemon if there is a configured interface that is not declared. The range is needed only if you want to serve addresses on that interface. > Maybe I need to really figure out the netmask thing. Is the netmask > that is part of the subnet declaration different from the 'option > subnet-mask' statement? Yeah, this is getting a bit tricky since you've got such a huge subnet. I'll post any ideas that might occur to me. jc -- Jeff Coppock Systems Engineer Diggin' Debian Admin and User
