[Dnsmasq-discuss] Dnsmasq not answering DHCP requests

Sun Feb 7 07:25:20 GMT 2010

Hi Richard,

> Oh, that might be the problem.  Try ipconfig /release and then 
> ipconfig /renew.  If you don't release the lease, the old lease is 
> still valid and Windows will unicast renewal requests and not go 
> looking for a new server.  If you first release the old lease then it 
> will broadcast and get a lease from any available server.

It works! I tried again in the morning and my clients got correct IP addresses from dnsmasq.

Thanks a lot for your help!

Regards, Robert

-------- Original-Nachricht --------
> Datum: Sun, 7 Feb 2010 01:07:06 -0600
> Von: "richardvoigt at gmail.com" <richardvoigt at gmail.com>
> An: Robert Pollai <rap.nospam2 at gmx.net>
> CC: dnsmasq-discuss at lists.thekelleys.org.uk
> Betreff: Re: [Dnsmasq-discuss] Dnsmasq not answering DHCP requests

> On Sat, Feb 6, 2010 at 4:21 PM, Robert Pollai <rap.nospam2 at gmx.net> wrote:
> > Hi Richard,
> >
> >> This sounds as if some other DNS and DHCP server programs are running.
> >> Or perhaps dnsmasq is running and owns the ports, but is reading from
> >> a different configuration file (path can be specified on the
> >> command-line, there's also a compiled-in default).
> >
> > I verified that when I stop dnsmasq, the ports disappear from netstat
> -l. When I start dnsmasq they come back. So it looks like dnsmasq has them.
> >
> > I start it via the following command in a script:
> >
> > /volume1/@appstore/dnsmasq/bin/dnsmasq -C
> /volume1/@appstore/dnsmasq/etc/dnsmasq.conf
> >
> > For testing purposes I now added logging:
> >
> > /volume1/@appstore/dnsmasq/bin/dnsmasq -C
> /volume1/@appstore/dnsmasq/etc/dnsmasq.conf --log-facility=/volume1/@appstore/dnsmasq/log/dnsmasq.log
> --log-dhcp
> >
> > I get the following output:
> >
> > Feb  6 23:13:08 dnsmasq[17719]: started, version 2.52 cachesize 150
> > Feb  6 23:13:08 dnsmasq[17719]: compile time options: IPv6 GNU-getopt
> no-DBus no-I18N DHCP TFTP
> > Feb  6 23:13:08 dnsmasq-dhcp[17719]: DHCP, IP range 192.168.0.100 --
> 192.168.0.150, lease time 12h
> > Feb  6 23:13:08 dnsmasq[17719]: using nameserver 195.202.128.2#53
> > Feb  6 23:13:08 dnsmasq[17719]: using nameserver 195.202.128.3#53
> > Feb  6 23:13:08 dnsmasq[17719]: using nameserver 62.40.128.2#53
> > Feb  6 23:13:08 dnsmasq[17719]: read /etc/hosts - 2 addresses
> >
> > This shows that it reads the correct config file (it has DHCP and the
> name servers).
> >
> > Still, when I start "ipconfig /renew" on a Windows client after
> disabling the DHCP server in the router the request times out. I already put in
> dhcp-authoritative in the config file to get dnsmasq to take over everything
> from the old DHCP server immediately.
> 
> Oh, that might be the problem.  Try ipconfig /release and then
> ipconfig /renew.  If you don't release the lease, the old lease is
> still valid and Windows will unicast renewal requests and not go
> looking for a new server.  If you first release the old lease then it
> will broadcast and get a lease from any available server.
> 
> >
> > So right now I am a bit clueless. I will leave the DHCP in the router
> switched of and dnsmasq running overnight, maybe the client needs more time
> to realize that the old DHCP server is gone.
> >
> > Of course any further advise is greatly appreciated.
> >
> > Kind regards, Robert
> >
> > -------- Original-Nachricht --------
> >> Datum: Sat, 6 Feb 2010 11:35:54 -0600
> >> Von: "richardvoigt at gmail.com" <richardvoigt at gmail.com>
> >> An: Robert Pollai <robert.pollai at gmx.at>
> >> CC: dnsmasq-discuss at lists.thekelleys.org.uk
> >> Betreff: Re: [Dnsmasq-discuss] Dnsmasq not answering DHCP requests
> >
> >> On Sat, Feb 6, 2010 at 1:53 AM, Robert Pollai <robert.pollai at gmx.at>
> >> wrote:
> >> > Hi Richard,
> >> >
> >> > Thanks for your reply!
> >> >
> >> >> Is dnsmasq running on the router where the old DHCP software was?
>  A
> >> >> separate computer?  Connected how to the network? (e.g. dnsmasq is
> >> >> wired to the router, clients are a mix of wired and wireless)
> >> >
> >> > The previous DHCP server was a router appliance from Linksys. Dnsmasq
> >> > I run on a NAS from Synology (DS408) with an PPC processor running
> >> Linux.
> >> > I compiled dnsmasq there myself. The NAS is wired to the router and
> all
> >> > clients I tested so far are wired to the router as well.
> >> >
> >> >> What OS?  Could be a firewall/packet filtering issue on either the
> >> >> dnsmasq computer or the router. (e.g. router firewall is configured
> to
> >> >> accept DHCP requests but not bridge them to the rest of the network)
> >> >
> >> > I also tested a client that is connected directly to the NAS via a
> >> switch,
> >> > So there is no firewall between. The firewall on the NAS is disabled.
> >> >
> >> >> Make sure that dnsmasq owns port 67 on its machine by running
> "netstat
> >> >> -l" with dnsmasq running and again with dnsmasq stopped.
> >> >
> >> > I did that and dnsmasq has port 67 (shown as "bootps") and also 53
> >> (shown
> >> > as "domain") for DNS. I tested DNS and it works for machines I have
> in
> >> my
> >> > /etc/hosts (after I commented no-hosts out of the config file). The
> DNS
> >> > does not work for the names I put in via the dhcp-host entries.
> >>
> >> This sounds as if some other DNS and DHCP server programs are running.
> >>  Or perhaps dnsmasq is running and owns the ports, but is reading from
> >> a different configuration file (path can be specified on the
> >> command-line, there's also a compiled-in default).
> >>
> >> How are you starting dnsmasq?  Does it behave differently if you run
> >> it from a root command-line instead of through init scripts?
> >>
> >> >
> >> > Kind regards, Robert
> >> >
> >> > -----Original Message-----
> >> > From: richardvoigt at gmail.com [mailto:richardvoigt at gmail.com]
> >> > Sent: 05 February 2010 23:47
> >> > To: rap.nospam2 at gmx.net
> >> > Cc: dnsmasq-discuss at lists.thekelleys.org.uk
> >> > Subject: Re: [Dnsmasq-discuss] Dnsmasq not answering DHCP requests
> >> >
> >> > On Fri, Feb 5, 2010 at 3:24 PM,  <rap.nospam2 at gmx.net> wrote:
> >> >> Hi,
> >> >>
> >> >> I am new to dnsmasq and want to replace my routers DHCP with it. So
> I
> >> just tried to create my first setup but unfortunately it seems that
> dnsmasq
> >> is not answering DHCP requests, my clients requests are timing out.
> >> >>
> >> >> I would appreciate any hints on what I could have done wrong or
> >> generally on how to approach/debug the issue.
> >> >
> >> > Is dnsmasq running on the router where the old DHCP software was?  A
> >> > separate computer?  Connected how to the network? (e.g. dnsmasq is
> >> > wired to the router, clients are a mix of wired and wireless)
> >> >
> >> > What OS?  Could be a firewall/packet filtering issue on either the
> >> > dnsmasq computer or the router. (e.g. router firewall is configured
> to
> >> > accept DHCP requests but not bridge them to the rest of the network)
> >> >
> >> > Make sure that dnsmasq owns port 67 on its machine by running
> "netstat
> >> > -l" with dnsmasq running and again with dnsmasq stopped.
> >> >
> >> >>
> >> >> Here is my config file:
> >> >>
> >> >> - file start -
> >> >>
> >> >> # Configuration file for dnsmasq.
> >> >> #
> >> >>
> >> >> dhcp-range=192.168.0.100,192.168.0.150,12h
> >> >> dhcp-leasefile=/var/packages/dnsmasq/target/leases/dnsmasq.leases
> >> >> dhcp-authoritative
> >> >>
> >> >> no-resolv
> >> >> no-hosts
> >> >>
> >> >> server=(ip deleted)
> >> >> server=(ip deleted)
> >> >> server=(ip deleted)
> >> >>
> >> >> dhcp-option=option:router,192.168.0.1
> >> >>
> >> >> dhcp-host=(mac deleted),adam,192.168.0.100
> >> >> dhcp-host=(mac deleted),eva,192.168.0.101
> >> >>
> >> >> - file end -
> >> >>
> >> >> Kind regards, Robert
> >> >>
> >> >> _______________________________________________
> >> >> Dnsmasq-discuss mailing list
> >> >> Dnsmasq-discuss at lists.thekelleys.org.uk
> >> >> http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
> >> >>
> >> >
> >> >
> >> >
> >>
> >> _______________________________________________
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> >