detect new devices on network

Steve Lancaster stevelan at
Wed May 14 16:57:48 UTC 2008

I've done this by watching the log output. I set up the server with no
range statement. Each request then results in a "no free leases"
message. In order to give hosts fixed addresses, based on the port on
the switch they are plugged into, I do an SNMP query, matching the mac address
with the port number. I then insert a host record for that host with the 
address reserved for that port, and the next  time the device makes a dhcp 
request, they get the "fixed" address assigned.

With newer switches, I use the option 82 capability to do the same thing
based on a class per port.


[In a message on Wed, 14 May 2008 11:48:32 EDT,
  "Gerry Reno" wrote:]
>Hello all,
>  Is there a way with any dhcp server that I can know when dhcp gave out 
>a new lease to a new device?  When someone plugs in a pc, phone, laptop 
>to the network I'm looking for a way that I can receive notification of 
>the event and the ip assignment.


More information about the dhcp-users mailing list