Insert delay in dhcp3-relay ?

Simon Hobson dhcp1 at
Wed May 4 06:53:43 UTC 2011

Benjamin wrote:

>I would like to know if it's possible to add a delay before 
>forwarding the query in the dhcp relay ? Because my client use the 
>relay in place of my primary DHCP server ... so if I can add a delay 
>my client will use my primary server.

Can you clarify your setup, and what the actual problem is ?

Clients do not "choose" a relay or server, they simply broadcast 
requests and *ALL* relays and servers will receive it. Some may 
choose to ignore it for some reason, but all will receive it.
So if you have two relay agents serving a network, or a relay agent 
in the same network as the server, then the server(s) will receive 
more than one copy of a broadcast request. That is normal.

Once a client has an active lease then it will periodically attempt 
to renew it. These renewals, while the lease is still active, are 
initially made by unicast to the server that issued the lease - and 
relay agents don't get involved, neither do other DHCP servers. If 
the issuing server doesn't respond, the client will eventually fall 
back to broadcasting a renewal request and other relay agents & 
servers then get involved.

Simon Hobson

Visit for books by acclaimed
author Gladys Hobson. Novels - poetry - short stories - ideal as
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