## Last updated : Mon Mar 11 15:52:43 1996 When the bootpc code fails to find a suitable server or reply it prints a message like: > Unable to locate an IP address for this host. > ***Please report this problem** > > [Unable to continue] > The client then goes into a loop forwever sleeping. The reason for this is that carrying on is probably foolish so it waits for a human to interrupt it and sort out the problem. If you really know what you are doing then you can set --returniffail to cause it to return. Using bootpc like this you can tell if your machine is connected to the network. I use this for machines which are sometimes on the net, but get taken home by their users sometimes. If it fails try running --debug --verbose to see if this sheds any light on the problem. The reasons it can fail that I've encountered are: o No bootp server is serving this client on this network x Set one up. If you want to disable networking if there is no reply to bootp see the --returniffails option. There is support for this in rc.bootp now. o Your default network card doesn't get you to the local network, or is filtered or firewalled and not letting bootp packets through. x Try using --server IPaddress of the server, check the routes you have set allow all broadcast route to the local network. o You are using --server to point to a server which doesn't run a bootp server x Try not using it. o Packets from bootpc don't reach the server, watching the network they seem to go somewhere else. x You have a default route set up which doesn't reach the bootp server. E.g. testing bootpc on a live system with the default route pointing at your external router. The rc.bootp script sets up a simple default route to the local net. If you can't see the bootp server from this you need a router which understands the bootp gateway protocol. For testing, just set --server to point at your local subnet's broadcast address. e.g. I use 131.111.16.255. o You are using --hwaddr and the bootp server responds directly to the MAC address quoted not to the machine generating the request. x Try not using it. In modern bootp servers you can tell it to broadcast the replies or reply to a known other address, this can be helpful for debugging. o The server doesn't understand RFC1497 cookies (you get not all the information back and a "WARNING bp_xid mismatch" probably.) x Install a newer bootp server, or make do with the information you can get from the old one. o The ping test fails with an "bootpc: unknown protocol icmp." error. x You don't have ICMP defined in /etc/protocols, fix it. If these don't seem to be the problem, use strace to trace the execution with --debug and --verbose and mail me the output, repeat also with --server IPaddress so I can try to see what went wrong. e-mail them to J.S.Peatfield@damtp.cam.ac.uk, I'll try to reply with suggestions or more questions pretty soon. -- Jon