difference between DHCPREQUEST sent through rely on rebinding and renewing

[Simon Hobson]

Nick Urbanik <nick.urbanik at optusnet.com.au> wrote:

> I have been asked what the difference is between the DHCPREQUESTs as
> seen through a DHCP relay by the server.
> 
> The reason for the question is that the number of instances of
> DHCPREQUESTs for clients in the rebinding state are reported to be
> about five times higher than the DHCPREQUESTs for the clients in the
> renewing state.

If you are looking only at requests that have been relayed, then I am not surprised. A client renewing any existing lease should not be using the relay at all as it should be unicasting the request to the server. If a lot of renewal requests are being received via the relay then that indicates that there may be a network problem preventing renewal by unicast and so the clients are (eventually) falling back to broadcasts which the relay agent can pick up.