Question about leases

[David W. Hankins]

On Mon, Apr 17, 2006 at 01:18:38PM -0400, Darren wrote:
> Further information.  On the router in question, it appears that it is 
> incrementing the secs field rather rapidly (or so an ethereal capture 
> suggests).  The value seems to be increasing as if it is usecs instead 
> of just secs (as RFC 2131 states it should be).  We saw values like 
> 11200 to  15689 in a one second time period.

Now I really want to see the packet trace, and anything you can find out
about the client make/model.

> If I set this:
> 
> load balance max seconds 30;
> 
> to:
> 
> load balance max seconds 0;
> 
> will that cause the DHCP server to ignore that setting and ignore the 
> secs field?

No, the fields are directly compared:

        if (state -> load_balance_max_secs < ntohs (packet -> raw -> secs)) {
                return 1;
        }

Since 0 is never less than 0, it will load balance the first message,
then nothing else (any nonzero secs field will get both servers to
respond).

You could set it to 65536 or greater (state->etc is an int, packet->secs
is a u_int16_t), but I wouldn't recommend it (you really want both servers
to answer after a few...sometimes one server can reach the client but the
other can't).

-- 
David W. Hankins		"If you don't do it right the first time,
Software Engineer			you'll just have to do it again."
Internet Systems Consortium, Inc.		-- Jack T. Hankins