Kind of sorted this. The Problem lay with mtu sizes & packets being dropped because fragmentation was needed & could not occur. For pptp clients trying to access certain sites & certain application through the e-smith box (example radmin remote control software), the packets had a large size, larger that the mtu of the ppp0 interface & were dropped. Solved the pptp client problem by adding in a line to the pptp-interface-access script in the events/action folder on e-smith. Changed it to the following:
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
# Technical support for this program is available from e-smith, inc.
# For details, please visit our web site at
www.e-smith.com or
# call us on 1 888 ESMITH 1 (US/Canada toll free) or +1 613 564 8000
#----------------------------------------------------------------------
package esmith;
use strict;
use Errno;
use esmith::util;
my $event = $ARGV[0] || die "Event name must be given\n";
my $ipparam = $ARGV[6] || "(none)";
exit 0 unless ($ipparam eq "pptpd");
my $interface = $ARGV[1] || die "Couldn't determine interface name\n";
my $verb;
if ($event eq "ip-down")
{
$verb = "--delete";
}
elsif ($event eq "ip-up.pptpd")
{
$verb = "--insert";
system("/sbin/ifconfig", $interface, "mtu", "1500");
}
else
{
die "Don't know what to do for event $event\n";
}
# Accept or cease to accept traffic on given interface as local traffic
system("/sbin/iptables", $verb, "INPUT", "-i", $interface, "-j", "ACCEPT");
system("/sbin/iptables", $verb, "OUTPUT", "-o", $interface, "-j", "ACCEPT");
exit(0);
Just altered the pppX to 1500 where pppX is the ppp interface for that particular vpn connection. I'm currently looking into how this alteration will affect throughput & performance but it seems okay for the moment (no smoke yet....)
Cheers