Re: xPL Perl

[Mark Hindess <xpl@xxxxxxxxxxxxxxxxx>]

On 7 December 2005 at 22:21, Ian Lowe <ianlowe@xxxxxxx> wrote:
> okay, need a little help here ;)
>
> The package installed fine, and the various commands are available
from
> the command line. (I'm running on Ubuntu Breezy, perl 5.8.7 for
> reference).
>
> Launching the hub, I'm using the command line -
>
> xpl-hub -i 192.168.1.20 -b 127.255.255.255
>
> as I read the -h output, that should be -i for the IP address to
listen
> on, (192.168.1.20 is my LAN IP), and -b is where to broadcast it - I'm
> using 127.255.255.255 as the loopback broadcast address.

This is related to the todo item I alluded to in my release note.  At
the moment these two parameters are really geared to specifying an
interface.  I was anticipating them being used to specify a single
interface... like the other linux toolkits I've looked at.  So at the
moment you'd have to specify:

xpl-hub -i 192.168.1.20 -b 192.168.1.255
xpl-logger -i 192.168.1.20 -b 192.168.1.255

That is, a single interface for all traffic.  There isn't currently
support for splitting the listen on and broadcast on interface/address.

To be honest, I'm not really sure about the best way to implement this
kind of flexibility intuitively as command line arguments.

While I see the advantage of using the loopback interface for
hub-to-client messages, clients should set remote-ip in hbeat messages
to the address they are listening on and I don't really like the
fact that hbeat messages would get transmitted with remote-ip set to
127.0.0.1 ... since this address is supposed to only be applicable to a
single host.

Unless I have a better idea in the meantime, the next release - in a few
days - will have an interface like:

# use interface eth0 for xPL broadcasts
xpl-hub -i eth0
xpl-logger -i eth0

I might add support for an optional -l (local) argument to allow the use
of a different interface for the hub-to-client messages:

# use interface eth0 for xPL broadcasts, but use interface lo for
# local hub-to-client messages
xpl-hub -i eth0 -l lo
xpl-hub -i eth0 -l lo

But getting the former to work will be my priority.

Regards,
Mark.