The macosxhints Forums - Get DHCP lease date

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- - Get DHCP lease date (http://hintsforums.macworld.com/showthread.php?t=59884)

Quote:

Originally Posted by CostasMan (Post 317925)

I had seen elsewhere mentioned the part about creating a new "location", and that seemed to fix his problem right away. I'm waiting on one user to bring his problematic laptop in to test this again. That solution kind of switches some of the suspicions back on the mac side?

Note that it isn't (I think) necessary to create a new location each time the problem occurs. It would seem that what you have found is that switching to a different "location" fixes the problem.
One thing that doing a "location" switch does is get a new DHCP lease.
The fact that requesting a new lease fixes the problem doesn't really throw any suspicion on the problem being on the Mac side.

And you still need to investigate why 'ping' fails when the Mac seems to have a valid IP address. Is there some network component that prohibits pings (or other transmissions) based on a blacklist or whitelist of MAC addresses or something?

Quote:

Originally Posted by CostasMan (Post 317930)

Another G5 got dropped from the network AND creating a new "location" did not cure the problem. I saw that he got a new IP address after I created the new location. Switching between the 'bad' and 'new' location did change IP addresses. When I created some more new 'locations', they would get the most recent IP.

I'm not sure I understand - if it didn't fix the problem, then the "new" location could also presumably be described as "bad".

But this gives you something to go on. DHCP servers are normally configured to give the same IP address to the same machine (based on the machine's hardware MAC address). So if switching to a new "location" (which requested a new lease) resulted in a change of IP address, that would seem to indicate that either the DHCP server is malfunctioning (or isn't configured the usual way) or that the previous IP address was not available (since it was found to be in use by some other machine on the network for example).

Check if the old IP address is now in use by some other machine.
(e.g. by pinging it, then looking at the results of 'arp -a')