Clients not recieving IP's via DHCP

Fri Feb 9 07:28:04 UTC 2007

Glenn Satchell wrote:

Hi Glenn,

First off thanks very much for your very informative e-mail.  I have
executed the tcpdump as suggested and get the following:

20:23:50.813845 IP (tos 0x0, ttl  64, id 17681, offset 0, flags [none],
proto 17, length: 328) 0.0.0.0.bootpc > 255.255.255.255.bootps:
BOOTP/DHCP, Request from 00:0d:3a:4e:f4:da, length: 300, xid:0xf4509737,
flags: [none]
          Client Ethernet Address: 00:0d:3a:4e:f4:da [|bootp]
20:23:50.827838 IP (tos 0x10, ttl  16, id 0, offset 0, flags [none],
proto 17, length: 328) 127.0.0.1.bootps > 192.168.2.252.bootpc:
BOOTP/DHCP, Reply, length: 300, xid:0xf4509737, flags: [none]
          Your IP: 192.168.2.252
          Server IP: 192.168.2.1
          Client Ethernet Address: 00:0d:3a:4e:f4:da [|bootp]

Once again it loops over 12 times with the only change of the id (from
the client) being incremented by 1 each time it loops.

I can't see anything regarding options from there I presume the flags
[none] is what I'm supposed to be paying attention to?

Also thanks Rudy and David for your suggestions.

Look forward to any further thoughts.

Cheers.

> Try capturing the requests from the client using tcpdump something like this:
> 
> tcpdump -n -v -i eth0 udp port 67 or 68
> 
> You're looking for the "dhcp-parameter-request-list", option 55. This
> lists all the parameters that the client wants. You need to make sure
> that you're specifying all of them. Probably the best way i sto look at
> an outgoing packet.
> 
> In ISC dhcpd the options are given names, rather than being referred to
> by a number. You can see the names and numbers in the file in the
> source distribution common/tables.c
> 
>          { "dhcp-parameter-request-list", "BA",          &dhcp_universe, 55 },
> 
> From this work out any missing parameters, then look for the format to
> specify them in the dhcpd.conf file using man dhcpd-options and man
> dhcpd.conf.
> 
> regards,
> -glenn
> 
>> Date: Thu, 08 Feb 2007 18:49:17 +1300
>> From: Tim Philips <timp at rndgroup.co.nz>
>> To: dhcp-users at isc.org
>> Subject: Re: Clients not recieving IP's via DHCP
>>
>> Hi All,
>>
>>
>> [sorry for the lengthy e-mail below]
>>
>>
>>
>> I'm trying to diagnose a very weird problem for a client.  They several
>> Windows Vista clients on their network and they are having problems
>> obtaining an IP address via DHCP (all other Windows XP and Linux clients
>> are working fine).
>>
>> To try and diagnose this outside of the clients production network I
>> have managed to replicate the problem in my personal network using my
>> XBOX and Nintendo Wii (based on the information below) (all other Linux,
>> Mac OSX and Windows clients work like a charm).
>>
>> The ISC DHCP version is 3.0.1-58.EL4 (installed from RPM on CentOS 4.4).
>> The basic configuration for the DHCP server is as follows:
>>
>> server-identifier router;
>> option domain-name-servers 192.168.2.1;
>> option routers 192.168.2.1;
>> option subnet-mask 255.255.255.0;
>> option broadcast-address 192.168.2.255;
>> default-lease-time 7200;
>> max-lease-time 50000;
>> ignore client-updates;
>> ddns-update-style none;
>> next-server 192.168.2.1;
>> authoritative;
>>
>> subnet 192.168.2.0 netmask 255.255.255.0 {
>>        range 192.168.2.100 192.168.2.150;
>> }
>>
>> host xbox {
>>        hardware ethernet 00:0D:3A:4E:F4:DA;
>>        fixed-address 192.168.2.252;
>> }
>>
>> When I enable DHCP on the XBOX and bring up the clients Ethernet
>> interface I see the following (as example) loops 12 times in the
>> messages file:
>>
>> Feb  8 18:28:37 thinktank1 dhcpd: DHCPDISCOVER from 00:0d:3a:4e:f4:da
>> via eth0
>> Feb  8 18:28:37 thinktank1 dhcpd: DHCPOFFER on 192.168.2.252 to
>> 00:0d:3a:4e:f4:da via eth0
>>
>> There is no firewall between the XBOX and the DHCP server.
>>
>> I have put another client (Linux) on the network and executed tcpdump
>> and I don't see anything coming back from the client after the DHCPOFFER
>> has been sent.  Looking on several mailing lists and google (and
>> friends) it indicates that the client may be expecting some additional
>> options that the DHCP server isn't sending but I can't for the life of
>> me figure out what.
>>
>> I have downloaded a Win32 DHCP client and installed that on a spare
>> Windows XP computer and right away the client was able to obtain an IP
>> address from the DHCP server, so I'm picking I have miss configured
>> something with the options for the given clients under ISC. I have even
>> attempted to set a static IP address on the client (which works fine).
>>
>>
>> Any clues that would help me solve the problem would be much appreciated!
>>
>>
>> Cheers ;)
>>
>> -- 
>>
>>
>> Thanks
>> Tim Philips (RHCE)
>> RND GROUP LIMITED
>>
>>
> 
> 

-- 

Thanks
Tim Philips (RHCE)
RND GROUP LIMITED