On Thursday 08 September 2005 16:18, Andrew McMillan wrote: > On Thu, 2005-09-08 at 09:59 -0300, Derek Broughton wrote: > > When I connect to my network at home through the lan (wired) connection > > of a Linksys WRT54G router, I get an address in the 192.168.1.* range, > > assigned by the DHCP server in the router. Next morning when I connect > > at work, dhclient immediately gives me the same IP. > > > > > > Sep 8 08:44:18 othello dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 > > port 67 interval 4 > > Sep 8 08:44:18 othello dhclient: DHCPOFFER from 192.168.1.1 > > Sep 8 08:44:18 othello dhclient: DHCPREQUEST on eth0 to 255.255.255.255 > > port 67 > > Sep 8 08:44:18 othello dhclient: DHCPACK from 192.168.1.1 > > > > > > What I should be getting is: > > > > Sep 8 08:46:12 othello dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 > > port 67 interval 3 > > Sep 8 08:46:12 othello dhclient: DHCPOFFER from 142.2.5.254 > > Sep 8 08:46:12 othello dhclient: DHCPREQUEST on eth0 to 255.255.255.255 > > port 67 > > Sep 8 08:46:12 othello dhclient: DHCPACK from 142.2.5.254 > > > > It would seem somebody's got a rogue DHCP server on our network, but what > > confuses me is that if I simply delete the /var/run/dhclient.eth0.leases > > file (which _only_ contains the address from the home DHCP server, > > nothing from previous connections to this subnet), the next time I run > > dhclient it finds the right DHCP server and assigns the right address. > > DHCP3 (at least) maintains a record of what your last lease and server > was. It tries to get _that_ lease back, and normally there won't be a > rogue server at the same IP serving out the same IP address to you, and > that will all be fine and dandy.
OK. That's good - because that's exactly what seems to be happening, but the man page implied that it only uses the lease file as a _last_ resort, not a first one. > > A rogue, however, often _will_ be on either 192.168.1.1 or 192.168.0.1 > as a default configuration. I would recommend you change your home > network to not get bitten by this again. For myself, the only time I > leave a router in such a default configuration is if there are only two > devices on that network. OK, makes sense. I think I can find a reasonable private IP range that isn't likely to come up more than once a millenium :-) > In receiving a DHCP response, DHCP3 may not be just taking the _first_ > server to respond - it can be waiting a little longer to see if it can't > get the same IP again from a different server. See the comment around > "select-timeout" in the dhclient.conf manpage - in my config it is set > to 2 seconds, but I'm not sure if that's the default, or if I fiddled > with it :-) Excellent. Thank you Andrew. You're the Man :-) -- derek -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
