On Wed, Jul 23, 2014 at 04:46:26PM +0200, Marcel Holtmann wrote: > Hi Michael, > > >>> I think the lease should be remembered and reused in this case. > >> > >> Hm, this sounds like a bug somewhere. When the new discover is sent > >> out it should send the same identifying information to the server, and > >> hence be given the same lease back again. Wireshark should tell you if > >> the fault is networkd's or the DHCP server. > > > > I get the same address at first, but after several minutes the DHCP server > > decides to offer a new address. I should note, that I have a 10 minute > > lease time for debugging purposes, so that might make the problem more > > prominent. I'll see if I can figure out what happens here. > > look at your DHCP server and see what lease time it really hands out after > reboot. > > However this is between you and your DHCP server. If you configure a lease > time of 10 minutes, then that is the only guaranteed time for a given IP > address. There is no mandate that the server has to give you the same address > after 10 minutes when you ask again. It is valid to just get a different one. > And that many home routers try to give you back the same one does not mean > that they are required to do so. > > The nice DHCP servers will remember your Ethernet address and/or identity > information and give you back your old IP address. Either with the left over > lease time or with a brand new lease time. There is really no need to store > this information on disk. If the lease expired the information on disk are > stale as well. And since our DHCP implementation is so fast, it makes really > no difference. > > It is safer start out with a brand new DHCP lease instead of having to deal > with renewal during boot. At least that way you know the DHCP server is still > there and you have a valid IP address. Just re-using a stored IP with a > left-over lease is not safe anyway. You never know what changed in the > network when you were off.
I think there was some misunderstanding here. I don't want to keep the lease across reboots. I don't care about that. I think networkd should remember the lease when restarting networkd only and not send a new dhcp discover. Michael -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ systemd-devel mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/systemd-devel
