libvirt conflicts with existing dnsmasq installation

[Alexey Kotlyarov]

Binary package hint: virt-manager

I have dnsmasq installed and running.

When creating (or starting) a virtual network with virt-manager, I get:

Error starting network: internal error 'dnsmasq --strict-order --bind-interfaces --pid-file=/var/run/libvirt/network/default_network.pid --conf-file= --listen-address 192.168.100.1 --except-interface lo --dhcp-range 192.168.100.128,192.168.100.254' exited with non-zero status 2 and signal 0:
dnsmasq: failed to bind listening socket for 192.168.100.1: Address already in use

The _virtual_ network, which NATs to physical interfaces, should not open any _listening_ ports on them.

ProblemType: Bug
Architecture: amd64
Date: Sat Dec 26 10:37:00 2009
DistroRelease: Ubuntu 9.10
NonfreeKernelModules: nvidia
Package: virt-manager 0.7.0-3ubuntu1
ProcEnviron:
 PATH=(custom, user)
 LANG=ru_RU.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-17.54-generic
SourcePackage: virt-manager
Uname: Linux 2.6.31-17-generic x86_64

[Chuck Short (zulcss)]

Looks like something is already binding to port 53. Can you attach the output of netstat -ap?

Thanks
chuck

[Alexey Kotlyarov (koterpillar)]

$ sudo netstat -apn | grep dnsmasq
tcp 0 0 0.0.0.0:53 0.0.0.0:* LISTEN 6890/dnsmasq
tcp6 0 0 :::53 :::* LISTEN 6890/dnsmasq
udp 0 0 0.0.0.0:53 0.0.0.0:* 6890/dnsmasq
udp6 0 0 :::53 :::* 6890/dnsmasq
unix 2 [ ] DGRAM 19903 6890/dnsmasq

But that is the point: I need that port. Libvirt should not.

[Soren Hansen (soren)]

I don't fully understand this bug report.

libvirt uses dnsmasq to provide dhcp services to virtual networks. It will not listen on 0.0.0.0. If you have a dnsmasq listening on 0.0.0.0, it's because you've installed the dnsmasq package yourself (libvirt pulls in dnsmasq-base, not dnsmasq) and let it be configured to listen to 0.0.0.0. If it does that, libvirt will not be able to bind to a port 53 on a specific interface.

[Alexey Kotlyarov (koterpillar)]

Thank you for the explanation, I have indeed configured dnsmasq incorrectly. My apologies.