Re: DCHP

[Ken Irving <fnkci@uaf.edu>]

Note - The convention on this list is to place your reply below previous
messages ("bottom-posting"), after also trimming the quoted part, so that
each message can be read top-down.  I've tried to reorder this reply that
way...

> 2008/3/14, Chris Henry <chrishenry.ni@gmail.com>:
>     On Fri, Mar 14, 2008 at 9:13 PM, Cassiel <raffaele.morelli@gmail.com>
>     wrote:
>     > Every time I restart my Lenny I obtain a new ip addr from one of the 2
>     dhcp
>     > servers. We have a 1 month lease on this servers and this should never
>     > happen within this period.
> 
>     You can't guarantee what IP address you'll receive with DHCP. If you
>     wanted to ensure static ip on your host, you should the following
>     lines to dhcpd.conf on the DHCP servers (if it is a linux/UNIX-based
>     dhcpd):
> 
>     host <hostname> {
>       hardware ethernet <MAC address>;
>       fixed-address <IP address>;
>     }
> 
>     That will ensure that your host (identified with MAC address) will
>     receive the same IP.

On Fri, Mar 14, 2008 at 03:47:26PM +0100, Cassiel wrote:
> Yes that's the point,
> I know you can map a mac address to ensure a static ip but my network admin
> said this should not be necessary because of the 1 month lease on the servers
> (running debian etch)
> 
> I must say I do not know how dchp works exactly, I am a poor web application
> developer :-)
> 
> So finally I guess this is the standard behaviour of a dhcpd daemon, at least
> on linux boxes?

The dhcpd daemon(s) is not on your box, so the behavior you're seeing
is due to whatever your admins are doing.  The DHCP client on your
box broadcasts a request for an IP address to the network, identifying
itself by the MAC address of your interface hardware.  The DHCP servers
should maintain a record of your MAC address, and should give you the
same IP unless that information expires (e.g., if you don't show up
for a month).  You say there are two DHCP servers; perhaps what you're
seeing is a different IP reply from one or the other server?  The admins
should be able to fix that; you could maybe force some workaround, but
really shouldn't have to.   This shouldn't have anything to do with what
OS you're running.

Ken

-- 
Ken Irving, fnkci+debianuser@uaf.edu