Hi, Apologies in advance for vagueness, but I have a question about dhcp. I have set up a system that is supposed to run unattended and automatically configure at boot, but there was a problem for which I had a cheesy workaround. My question concerns a) The problem, b) the workaround and c) does Windows do this?
Basically, as I understand it, if a Linux machine is configured as a DHCP client, and the DHCP server is unavailable at boot time (for example, the ethernet cable is not plugged in) then everything that loads up after that point gets a broken network configuration (something to do with resolv.conf I think). Plugging the cable back in has no effect, and there is no soft way of getting it configured again automagically because some software caches the broken configuration and won't flush it. (I tried looking for a Google reference, but can't find anything that describes this succinctly, and I'm not sure even sure I am describing it very well). Anyway, the solution is to reboot the machine and assume that fault goes away eventually. To that end my system literally does that- if networking is fundamentally broken at start-up, reboot. This is different from a network *becoming* broken, where it is sufficient to retry. It was a while since I worked on this, and it's all a bit vague. It was hard enough the first time round figuring out a good solution, and rebooting actually was the best way. If someone understands this problem, could you please give me a reference, to remind me why it is so fundamental. Also, is there a better solution than rebooting? I cannot put defaults in for dhcp, since the machine could move around so the defaults for one network make no sense for another. Andy
