Re: how to debug dhcp?

[dragoran <dragoran feuerpokemon de>]

dragoran wrote:
> David Timms wrote:
> > dragoran wrote:
> > > dragoran wrote:
> > > > John Reiser wrote:
> > > > > > when I try to use dhcp for my network device (eth0 - forcedeth) 
> > > > > > it does
> > > > > > not get an IP with the result: failed
> > > > > >     
> > > > >
> > > > >  
> > > > > > 2) how can I debug it to find out what is causing it?
> > > > > >     
> > > > >
> > > > > Boot single-user, invoke the dhcp program from a console in 
> > > > > "non-daemon"
> > > > > mode, and watch.
> > > > how do I do this (found nothing in the man page)
> > > > >   For dhcpd, consider flags -d -tf and perhaps -play.
> > > > > Also, consider running under strace.
> > > > I am talking about dhclient not dhcpd
> > > > >   For lowest-level packet trouble,
> > > > > use a program such as tcpdump or ethereal to check what goes over 
> > > > > the wire.
> > > > >
> > > > >   
> > > > used ethreal an have not found anything that looks like an error...
> > >
> > > this is what I get in /var/log/messages:
> > > Jul 19 09:08:39 chello062178124144 dhclient: DHCPDISCOVER on eth0 to 
> > > 255.255.255.255 port 67 interval 6
> > > Jul 19 09:08:45 chello062178124144 dhclient: DHCPDISCOVER on eth0 to 
> > > 255.255.255.255 port 67 interval 9
> > > Jul 19 09:08:54 chello062178124144 dhclient: DHCPDISCOVER on eth0 to 
> > > 255.255.255.255 port 67 interval 10
> > > Jul 19 09:09:04 chello062178124144 dhclient: DHCPDISCOVER on eth0 to 
> > > 255.255.255.255 port 67 interval 12
> > > Jul 19 09:09:16 chello062178124144 dhclient: DHCPDISCOVER on eth0 to 
> > > 255.255.255.255 port 67 interval 19
> > > Jul 19 09:09:35 chello062178124144 dhclient: DHCPDISCOVER on eth0 to 
> > > 255.255.255.255 port 67 interval 5
> > > Jul 19 09:09:40 chello062178124144 dhclient: No DHCPOFFERS received.
> > >
> > > wtf?
> > > who is broken here? should I fill a bug?
> > Can you run ethereal on the dhcp server {or a third machine} to 
> > ensure the packets get to the server ?  firewall stopping udp port 67 
> > or 68 at either end ? Slow negotiating switch or mismatched port 
> > speeds ?
> > Is the DHCP server set to be authoritative; ? Without this I believe 
> > win {for eg} tries hard to use any previous dhcp it last received, 
> > not sure about fc-whatever.
> > At the server should see:
> > DHCP Discover -> server
> > client        <- DHCP Offer
> > DHCP Request  -> server
> > client        <= DHCP ACK
> >
> > DaveT.
> the problem is that I havn't any access to the server (its the ISPs 
> dhcp server)
any idea how to get this working? it works well on windows (same nic, 
same network)