[Dnsmasq-discuss] dnsmasq w/Upstream DHCP

[Michael Convey]

Richard,

I am working through Red Hat technical support and the CentOS forums (among
other things). However, finding answers has been slow and challenging. I am
hoping someone on this mailing list will have some useful insights to help
me resolve my issues.

Michael



On Thu, Nov 4, 2010 at 2:17 PM, richardvoigt at gmail.com <
richardvoigt at gmail.com> wrote:

> These are all questions about when RedHat consults dnsmasq, not what
> dnsmasq does.  It's not dnsmasq's job to "force nslookup to" anything.
>
> You should consult resources on configuring RHEL for solutions to
> these problems (for one thing, the solution is the same whether you're
> running ISC Bind, dnsmasq, some other DNS service, or want to use a
> different non-local DNS server than the one listed in your upstream
> DHCP).
>
> On Thu, Nov 4, 2010 at 3:21 PM, Michael Convey <smconvey at gmail.com> wrote:
> > I'm using dnsmasq for small virtual network (one RHEL 5.5 machine acting
> as
> > a Xen host - hostname: server.exampe.com - with two Xen guests). IP
> > addresses of the virtual network are statically assigned and maintained
> in
> > the /etc/host files. My /etc/hosts file reads as follows:
> >
> > # Do not remove the following line, or various programs
> > # that require network functionality will fail.
> > 127.0.0.1               localhost.localdomain localhost
> > ::1                     localhost6.localdomain6 localhost6
> > 192.168.122.1   server.example.com      server
> > 192.168.122.2   centos.example.com      centos
> > 192.168.122.3   fedora.example.com      fedora
> >
> > I'm not using dnsmask's DHCP functions. However, my machine is part of an
> > external network that uses DHCP (Windows). Even with dnsmasq on, nslookup
> > showed my system was favoring the upstream DNS servers. So, I did the
> > following:
> >
> > 1) in /etc/sysconfig/network-scripts/ifcfg-eth0, I added the line
> > "DNS1=127.0.0.1"
> > 2) in /etc/dnsmasq.conf, I uncommented the line "strict-order"
> > 3) in /etc/dhclient-eth0, I added the following line: supersede
> > domain-search "";
> >
> > After a network restart, my resolv.conf file read as follows:
> >
> > ; generated by /sbin/dhclient-script
> > nameserver 127.0.0.1
> > nameserver 10.10.15.10      #upstream DNS server via DHCP
> > nameserver 10.125.110.44       #upstream DNS server via DHCP
> >
> > Sometimes the resolv.conf spontaneously changes back to all upstream
> > nameservers (drops the 127.0.0.1). If I do a network restart it comes
> back.
> > How is the "DNS1=127.0.0.1" in /etc/sysconfig/network-scripts/ifcfg-eth0
> > overridded? Could this be related to upstream DHCP lease renewal?
> >
> > Also, even when the resolv.conf file reads as above, 'nslookup
> > server.example.com' or 'nslookup 192.168.122.1' gives the following:
> >
> > # nslookup 192.168.122.1
> > Server:         10.10.15.10
> > Address:        10.10.15.10#53
> >
> > ** server can't find 1.122.168.192.in-addr.arpa.: NXDOMAIN
> >
> > # nslookup server.example.com
> > Server:         10.10.15.10
> > Address:        10.10.15.10#53
> >
> > ** server can't find server.example.com: NXDOMAIN
> >
> > Why doesn't dnsmaq force nslookup to first check /etc/hosts?
> >
> > _______________________________________________
> > Dnsmasq-discuss mailing list
> > Dnsmasq-discuss at lists.thekelleys.org.uk
> > http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
> >
> >
>
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