What is the best way to monitor list of current leases and their states?

[Jerimiah Cole]

michael kapelko wrote:
> We use DHCP with Relay Agent Info option, because we have a network of
> D-Link's. We would like to see what IPs have been offered to a certain
> switch port. Is that possible?
> So far I came up with these possibilities:
> 
> 1. dhcpd.lease
> The lease file seems to be a history and doesn't seem to be a 'fast'
> option for monitoring states.

All of the current leases are stored in the leases file, including the 
relay agent info:

lease 10.9.100.1 {
   starts 3 2009/06/10 15:49:48;
   ends 3 2009/06/10 23:49:48;
   tstp 3 2009/06/10 23:49:48;
   binding state active;
   next binding state free;
   hardware ethernet 00:13:ba:20:04:9a;
   uid "\000\023\272 \004\232";
   option agent.circuit-id "vdsl-01-01/Ethernet8:Vlan2";
   client-hostname "ON2342";
}

Should be easy to parse and sort/search by port.

Jerimiah