[techtalk] Thanks for the help, Folks

[Techno]

Thanks for the replies to my query this morning, people.

The system is up again, but the worrying thing is that we're STILL not sure
what the problem was, other than we know that packets weren't being
forwarded through my Gateway.

All the IP Forwarding indicators were turned on
(/proc/sys/net/ipv4/ip_forward set to 1, FORWARD_IPV4="yes"), and I'd
re-booted the machine to reset any transient problems, but the forwarding
just wasn't there until about 1/2 hour ago.

After exhausting all avenues myself, I ended up calling in a friend who's
been running a Linux Consulting Company for several years now ( he didn't
get me into Linux, but he helped me develop over the years ), he went
through all the same steps & came to the same decision (no forwarding, but
nothing to indicate WHY on my server, even though he told me it was my box,
rather than the routing setup at the time), so HE called the ISP to tell
them that there appeared to b a problem at their end, and went though all
the same steps I had earlier, at least he managed to get them to re-start
their router, at which point the packet forwarding FINALLY re-started.

So, it appears that my packets were going into a black hole SOMEWHERE
between my Gateway & their router, at least it's up again, though it would
have been nice to find out where the problem really was. All I can say for
sure is that nothing at my end was changed at all, it worked, it didn't,
then it did again, so I STILL think the problem was at their end.

Anyway, thanks again to everyone who offered advice and assistance.

NB: It appears to be the IP Forwarding crunch time, someone else has just
posted the same query. ;^)

Regards.

Neale