[Techtalk] "bind to reserved port" error

[Wim De Smet]

On 3/27/07, David Sumbler <david at aeolia.co.uk> wrote:
> On Tue, 2007-03-27 at 15:09 +0200, Wim De Smet wrote:
> > On 3/27/07, David Sumbler <david at aeolia.co.uk> wrote:
> > > I am running Ubuntu 6.10, and have plptools installed.  This is a
> > > collection of programs for connecting to a Psion hand-held computer.  I
> > > have used it before under Fedora.
> > >
> > > In order to connect to the Psion, which is connected to /dev/ttyS0, a
> > > daemon called 'ncpd' is run.  This seems to be working
> > > fine: /var/log/daemon reports:
> > >
> > > daemon started. Listening at 127.0.0.1:7501 using device /dev/ttyS0
> > > Connected with a S5 at 115200baud
> > >
> > > (S5 is the variety of Psion computer that I have.)
> > >
> > > In order to read the files on the Psion, I then have to run another
> > > daemon called 'plpnfsd'.  Although it prints an encouraging message on
> > > the screen, it actually exits immediately.  The log file reports:
> > >
> > > connected, status is 0
> > > bind to reserved port: Permission denied
> > >
> > > I have tried running ncpd and plpnfsd using an arbitrary different port,
> > > but with exactly the same results.
> > >
> > > My firewall settings seem to be fine, so far as I can tell.
> > >
> > > Can anyone shed any light on why the port is reported as "reserved"?
> >
> > All ports under 1024 are reserved, this means only root can bind to
> > them. You probably need to convince this second daemon to use one of
> > the ports above 1024, or run it as root.
>
> But the port being used is 7501.  I have also tried other arbitrarily
> chosen ports - e.g. 8513 - with the same result.

The first daemon binds succesfully to this port yes, you don't need to
change that.

>
> If I run plpnfsd as root, it appears to hang for a couple of minutes,
> but it does eventually make the connection successfully, and goes into
> the background.

plpnfsd is probably trying to register another port and that's where
things are going wrong. I'm not intimate with the software but
depending on what it does you either need to run it as root or find a
way to have it bind to another port. Mind you this is not port 7501
which is claimed by ncpd. At least that's how I understand it from
your previous mail.

greets,
Wim