On Thu, 2002-10-17 at 18:23, José Luis Gómez Dans wrote: > Alex Hudson wrote: > > Hi José - I don't really understand your question :) > > I know, I am not particularly sure of what happened :-) Hehe ;) It does sound odd... > unreachable and so on. On closer in situ inspection, it was clear that > the eth0 interfaces (at least in the one that has a keyboard and > monitor :D) were not configured (/sbin/ifconfig showed no IP address). Ah. Probably, the DHCP server was down longer than the lease time - you obviously have to give up the lease at the end, so the device would be deconfigured. However, the DHCP client should keep trying to re-acquire the lease - I'm not sure for how long or how quickly though; it may well back-off. The RFC indicates exponential backoff; in real life that probably means unless it can contact the DHCP server within a reasonable frame of time (e.g., 4-8 hours) it's unlikely to be trying very hard. DHCP leases of <12 hours seems unreasonably small - usually, leases are days long for just this reason (i.e., being able to fix a dhcp server and not lose network :) > My previous message was probably a bit vague, as I do not know the > details of what happened, but the question stands on how to deal with > this automatically. Rather than ping, you can probably just chink the dhcp client around a bit. However, I don't think there's an answer - the problem is the small leases, and to conform to the rfc you probably can't squeal too loudly if you can't contact the server: you have to wait until it comes back up anyway. Unfortunately, DHCP is a bit of a rubbish protocol, and you're hitting one of it's deficiences. It's extremely difficult to make DHCP fault tolerant, because you cannot (by protocol) balance a single net across a number of servers, and hence when they go down you get problems. The traditional 'paper over the cracks' solution is to make the lease very long - you might want to suggest that to your network people? Cheers, Alex.
Attachment:
signature.asc
Description: This is a digitally signed message part