I am attempting to reproduce a condition in a lab and am hopeful to find a DHCP Server in which I can configure it to hand out tiny leases (20 seconds). So far, all I can find will not hand out leases smaller than one minute.
To be sure, this is part of a larger issue I am helping a firewall vendor reproduce. I'm trying not to go into overwhelming detail, but in essence what's going on is this.
Residential cable modems, when they have no sync on the cable side, will hand out a private IP in response to a DHCP Discover. The offer has the private IP with a tiny 20 second lease. The firewall/router is supposed to ask for a new IP/lease after the expiration. Two routers I have tested do. My firewall vendor's device does not seem to do this. Instead it hangs onto the private IP and never assigns the WAN IP after the cable modem has synced.
The vendor is trying to reproduce this behavior in their lab. I'd like to try as well. The first step, I think is to find a DHCP Server in which I can configure these tiny leases. I have a suspicion that the firewall is not honoring the tiny lease.
Anyone aware of a DHCP server like this? Windows or Linux.
Debian's dhcp3-server package has lease times measured in seconds, but I don't know if the minimum is really 1 second. Worth a try, at least.