helpfor option ping-check

Simon Hobson dhcp1 at
Mon Jul 1 07:19:17 UTC 2013

Julie Xu wrote:
>So looks like the client ID same on two PC is the problem someone manually setup like this? Please confirm.

We don't know - none of us can look at the logs and lease file on your machine !

The quickest way to see if this is the problem is to look at the leases file. Take a copy, open it in an editor, jump to the end and do a reverse search* for the IP address (in vi this would be "G" to jump to the end, then "? nnn.nnn.nnn.nnn" to reverse search for an IP (replacing nnn with the real numbers of course).

See if there is a Client-ID recorded for either/both of the two clients - you will have to differentiate them by their MAC address. If you find a lease for two clients (according to MAC) but the same Client-ID then that is your problem. If not, then it isn't.

* Reason for reverse search is that the lease file is a log file - all new lease information is updated by adding a new record on the end. By searching backwards from the end you will see the most recent (ie current) version first.

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