Simon Hobson dhcp at
Sat May 27 09:14:53 UTC 2006

Howard Wang wrote:

>Do you know if the client made the request ?
>unfortunely no, the client is etherboot, not many information can be seen.

In that case, a packet sniffer (eg ethereal) is your friend.

>Anything else logged immediately before or after this - especially
>anything dns related ?
>nothing from /var/log/messaes
>Do you supply any different options using static address vs dynamic address ?
>the manual config does work. lets say, I specify the client MAC in dhcpd.conf,
>the server is able to get the DHCPREQUEST and then send DHCPPACK, the client
>picks the address.

AT this point I need to correct something. You talk of "the server is 
able to get the DHCPREQUEST" as though this is something the server 
does. The server is passive in this, if the client sends it, the 
server will get it, if the client doesn't send it, there's nothing 
you can do at the server end to fix this - apart from ...

figure out why the client is not accepting the offer.

Firstly, look carefully at your server config, and see if the options 
send when specifying a fixed address are in any way different to 
those sent when using a dynamic address. You could post your config 
file here and we can take a look.

Next, you could look at the packets on the wire and see what is sent 
out - compare the offer packets for the two cases and see what's 
different. With ethereal installed, 'tethereal -V -f "ether host 
aa:bb:cc:dd:ee:ff and (port 67 or port 68)"' should do it.

The only explanation I can see is that in the two cases, the offer 
packet differ in more than just than IP address and the client is not 
happy with one of them.


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