Arch Linux

Description:

The libvirt network on a local machine started failing after a recent upgrade (last week).

Investigating, it turned out that DNS was no longer functional, and restarting dnsmasq fixed the issue.

An hour later, the problem returned.

I again restarted dnsmasq with the libvirt options, but added the --no-daemon option. After a while, it started producing messages that the maximum number of concurrent DNS requests had been reached. I restarted dnsmasq again, this time adding the -q option (to also log queries); at this point, the following started showing up:

dnsmasq: query[AAAA] opensuse-131-32 from 192.168.122.1
dnsmasq: forwarded opensuse-131-32 to 127.0.0.1
dnsmasq: query[AAAA] opensuse-131-32 from 192.168.122.1
dnsmasq: forwarded opensuse-131-32 to 127.0.0.1

etc. "opensuse-131-32" is the hostname of one of the machines on the libvirt network; i.e., it is a machine that dnsmasq handed out an IPv4 address for. Notice the fact that a quad-A record is asked, however.

Additional info:
* package version: 2.71-1

Steps to reproduce:
* Install libvirt, make sure libvirt default network is started (should start dnsmasq with "--conf-file=/var/lib/libvirt/dnsmasq/default.conf --dhcp-script=/usr/lib/libvirt/libvirt_leaseshelper"
* Start a VM, have it do a DHCP request
* Try to resolve the IPv6 address of that VM's hostname more than 150 times.
* Watch dnsmasq explode (sortof)

libvirt's default.conf and libvirt_leasehelper are attached