Command line tool for emulating DHCP-client

Tim Peiffer peiffer at
Fri Aug 24 16:13:04 UTC 2007

There are multiple methods to do what you request. The one I have used 
is dhcping.

That said, why? I know you said you wanted to send a DHCPRELEASE on 
behalf of the clients. That is fine for cleaning up a lease database, 
but the release information is never sent back to the client, and the 
client does not know that its lease is no longer valid. If the client 
presents with the same address through a DHCPREQUEST, the DHCP server is 
supposed to honor it, presuming the lease isn't already in use, and that 
the address is consistent with the network that sourced the DHCPREQUEST. 
In my opinion, unless the client is given a new lease on another network 
or from another part of the pool, sending a DHCPRELEASE breaks the 
protocol assumptions.

Tim Peiffer
Network Support Engineer
Networking and Telecommunications Services
University of Minnesota/Northern Lights GigaPOP

dhcping - send a DHCP request to DHCP server to see if it’s up and
The client either sends a DHCPREQUEST or DHCPINFORM packet to the
server and waits for an answer. Then, if a DHCPREQUEST was send, it
will send a DHCPRELEASE back to the server.

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