On Wed, Oct 22, 2008 at 02:16:10PM -0400, James Carlson wrote: > > There is another not-a-band-aid option: don't release the lease on > > shutdown if proper shutdown past the killall step depends on networking. > > > > Not releasing a lease is anti-social, but arguably less so than > > continuing to use the IP address past releasing it. Then again, I think > > most DHCP servers and networks using DHCP will tolerate brief uses of > > IP addresses past release. > > Note that in the solution described in the original project (the one > just approved by PSARC), we do not release the lease or clear out the > interface before exiting. I think that's actually the safest thing to > do, and the most in tune with the standards.
That wasn't clear to me because the case materials simply spoke of not "canonizing" a DHCP interface when a new ioctl indicates that iSCSI depends on it, and it defined "canonizing" as resetting the interface to 0.0.0.0. If the actual proposal is to not release the lease, then I think that's a fine proposal. > Releasing the lease and continuing to use the address would not just > be an "anti-social" thing to do, but it could also cause real failures > on networks with address use pressure, and would almost certainly > cause us to fail various compatibility and conformance tests (like > those at UNH). > > That doesn't seem like a good path to me. I agree. An option to set negatively extend the lease time to now+5m or some such suitable value could be handy. I don't know if it's possible to use DHCP option 58 (or some other option) in this way in a DHCPREQUEST. In any case, if we're really worried about continuing to use an address after the lease expires, then one'd think it'd be good for the kernel to enforce lease expiration just in case dhcpagent died hard and isn't getting restarted. Nico -- _______________________________________________ networking-discuss mailing list [email protected]
