I have an Ubuntu Noble/24.04 server managing my network. It runs DHCP,
DNS, and samba. Several Linux machines and one Windows machine are
connected to it via a gig switch. The machines on the switch get access
to the rest of the world through packet forwarding on the Linux server.
In other words, I run my own router.
Periodically, the network just goes down. None of the machines can talk
to each other. Power cycling the switch doesn't help. Restarting network
services on the Linux box doesn't help. I even tried unloading the
kernel driver for the ethernet card on the Linux box and reloading it.
# rmmod e1000e
# insmod e1000e
No joy. The only thing that seems to work is rebooting the Linux box. I
was beating my head against the wall for weeks. Bought a new switch, did
everything I could think of. Then, just to keep the Windows machine from
being effected, I connected it directly to a port on the router supplied
by my ISP, AT&T. Then the AT&T router started going down. My own network
was uneffected. I had to power cycle the AT&T router to fix it. I put
the Windows machine back on my own network and the problem began again.
So now I know that this Windows machine is doing something to the
network to make a router freeze. How is that even possible? If it is
static or something, why wouldn't that effect the switch instead?
Whatever is happening has to go from the Windows machine, through the
switch, to the Linux server, and effect it in such a way so that even
reloading the kernel module for the network card doesn't fix the problem.
Anybody got an explanation for that? Any ideas at all?
PS: If you are wondering why I am essentially building my own router
instead of just connecting everybody directly to the AT&T router, it's
because this setup is left over from the days of dial-up modems. At one
time, we had a Linux box with a 56K modem providing a network connection
we all shared. Anyone old enough to remember those days, someone would
be on-line and someone else would fire up their modem to get on-line.
That would disconnect the first person. So this was our solution. In
fact, it was a beautiful thing for years before ISPs started providing
smart routers. And now its so ingrained into our systems it is difficult
to get rid of.
