Estoy en 12.10, y siempre he usado dnsmasq. Hace unos días noté mensajes extraños durante el arranque:
NetworkManager[1316]: <warn> DNS: plugin dnsmasq update failed
dnsmasq[1302]: failed to create listening socket for 127.0.0.1: Address already in use
dnsmasq[1302]: FAILED to start up
NetworkManager[1316]: <info> DNS: starting dnsmasq...
NetworkManager[1316]: <error> [1362028900.869958] [nm-dns-dnsmasq.c:390] update(): dnsmasq not available on the bus, can't update servers.
NetworkManager[1316]: <error> [1362028900.869979] [nm-dns-dnsmasq.c:392] update(): dnsmasq owner not found on bus: Could not get owner of name 'org.freedesktop.NetworkManager.dnsmasq': no such name
NetworkManager[1316]: <warn> DNS: plugin dnsmasq update failed
dnsmasq[1876]: warning: no upstream servers configured
Aquí está mi /etc/dnsmasq.conf: http://pastebin.com/AnKrrg6k
Aquí está mi /etc/dnsmasq.d/network-manager:
# Tell any system-wide dnsmasq instance to make sure to bind to interfaces
# instead of listening on 0.0.0.0
# WARNING: changes to this file will get lost if network-manager is removed.
bind-interfaces
Si necesita más información, por favor pregunte!