Insert delay in dhcp3-relay ?

Simon Hobson dhcp1 at
Wed May 4 20:35:47 UTC 2011

Benjamin wrote:

>When DHCP A is online a new time, I want the client uses DHCP A and 
>not the C (not necessary immediatly), for example after a reboot of 
>the client (for example after a night, the worker go to the company 
>and put  the computer on).
>After the reboot of the computer, the computer send on the broadcast 
>a "Request" (with the old IP address: ip address in the range of 
>DHCP C), so if I put a delay, the Relay not send the request to DHCP 
>C and after a few second the client send a "DHCP - Discover" (to 
>find a DHCP) and DHCP A send an offer, which the client accept 
>(Request - ACK ).
>But I can't put a delay ...

You may care to look at the min-secs statement. Adding this to the 
subnet declaration for the 'remote' subnet on each server should 
achieve what you want.
        The min-secs statement

           min-secs seconds;

           Seconds should be the minimum number of seconds since a client began
           trying to acquire a new lease before the DHCP server will respond to
           its  request.   The  number  of  seconds is based on what the client
           reports, and the maximum value that the client  can  report  is  255
           seconds.    Generally,  setting  this to one will result in the DHCP
           server not responding to the  client's  first  request,  but  always
           responding to its second request.

           This  can  be  used  to  set  up a secondary DHCP server which never
           offers an address to a client until  the  primary  server  has  been
           given a chance to do so.   If the primary server is down, the client
           will bind to the secondary  server,  but  otherwise  clients  should
           always  bind  to  the primary.   Note that this does not, by itself,
           permit a primary server and a secondary server to share  a  pool  of
           dynamically-allocatable addresses.

Simon Hobson

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