Maintained by: NLnet Labs

unbound listening sporadically on 0.0.0.0 high ports when configured for 127.0.0.1 ?

Robert Edmonds
Fri Jun 3 01:30:50 CEST 2016


Paul Wouters via Unbound-users wrote:
> On Fri, 3 Jun 2016, Daisuke HIGASHI wrote:
> 
> > Subject: Re: unbound listening sporadically on 0.0.0.0 high ports when
> >     configured for 127.0.0.1 ?
> 
> >   My guess is: UDP sockets for outgoing query
> > from Unbound to authoritative servers.
> > 
> >  I also see these "listening" UDP sockets at my laptop running unbound
> > when resolver is under load. And I see no them when no load.
> 
> That was my first thought too, but these entries do not have a
> destination IP or port, so it "appears" that these sockets are
> listening. Still it could be that perhaps these are sockets
> that are starting up for use or something?

Unbound doesn't connect() its UDP query sockets to the destination
IP/port, it uses sendto(), TTBOMK. So I wouldn't think the destination
would show up in netstat (or ss or lsof...) output.

-- 
Robert Edmonds
edmonds at debian.org