Gnarlodious wrote: > On 7/16/07, Thomas Jacob wrote: > >What makes you think that your router passes > >on DHCP requests? > Because computers connected to the modem will obtain a Linksys DHCP > range, and computer's connected to a Linksys router may obtain a modem > DHCP. > > I have a DSL modem/router at the terminal end of a chain of Linksys > routers, and the modem is not very configurable. I need to block DHCP > at the Linksys so the modem is invisible to the routers. I tried > disabling DHCP on the modem, but it has a server running from it and > the server requires DHCP to be running. I could let the router handle > the server's DHCP request, but then I would need to have another > device on the UPS battery. I want to have only two devices taking > power from the UPS battery, the modem and the server. A diagram might be more helpful. > Any help to solve this problem with software would be greatly > appreciated. These routers are Linksys WRT54GL with BusyBox v1.6.0 and > iptables v1.3.7. > > >On the contrary, one usually does have to put in > >a bit of effort to allow dhcp over routers (=> dhcp relay)... > In the BusyBox setup, DHCP broadcast is on by default, and apparently > a little hard to disable. DHCP is broadcast when one requests an IP. That's why it's D(ynamic)HCP. >From what it sounds like, you have several routers attached to the same network as the dsl modem. There's really no way to stop DHCP across that. The best way I can think of is to have a system (computer, router, whatever running linux) with 2 bridged interfaces and block DHCP traffic going across the bridge. I did this at work with a spare PC so that my part of the network would see my BOOTP server and not the DHCP server that is also on the network. (HINT, use ebtables!) -- Lab tests show that use of micro$oft causes cancer in lab animals Got Gas???
