LOL, you don't need any of that rubbish for running a home network.
Even with three or more switches
Typically, available cabling and physical barriers (aka walls) will stop you from creating loops even if you wanted to.
Sorry, comware is the type of operating system running on the switch. When 3com was aquired by HP, their OS was called comware to differentiate it from HPs existing switches. Comware is still in development to this day (but likely not long anymore) and i am familiar with it.
But that model pre-dates comware by quite a bit. According to the getting started guide i found, this thing is now almost 20 years old. It must have been one of the first gigabit switches.
I'm sorry, while i have worked with the command line of these a bit when i started my apprenticeship, i do not remember much about those.
Moving away from the default VLAN is a good idea for what you want to do. You might also try experimenting with turning off the broadcast storm protection. Should the connection cause a storm that is quickly obvious, since the port LEDs will go bonkers. Be carefult though, if the switch is conencted to the rest ob you home network, a broadcast storm might affect it.
After catching up with my sleep over the weekend, I moved my test network from VLAN2 to VLAN4, and moved main network from default VLAN1 to VLAN2.
It has the same problem. I patch cable between VLAN2 (now main) to VLAN4 (now test). Plugged into VLAN4, I can ping every one on VLAN4, but can't ping anyone on VLAN2, as if the patch cable isn't there. Storm-control (enabled or disabled) doesn't make any difference.
Maybe it has some mechanism to prevent establishing link with itself.
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Can you, with the patch cable disconnected, ping a VLAN4 host from another VLAN4 host at the same time as you are pinging a VLAN2 host from another VLAN2 host? Set up a continuous ping as described above and then connect the patch cable - what happens?
Are you using the same ip schema on both VLANs? If you're not, ping won't work, you can expect to get errors when you ping with the actual error depending on the configuration of the network AND the hosts.
Maybe it has some mechanism to prevent establishing link with itself. What if you join the VLANs through an intermediate switch?
(Kinda doesn't solve the problem of not wanting to have another switch around, I know, just a check ).
What's on the link status indicators and all that stuff?
Thanks for all the input. Good for my learning experience.
This switch doesn't have a log.
This switch doesn't have a log.
It almost certainly does, you just haven't found it yet.
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Done that (patch via switch) before and again today, as you say, just to check. No difference.
Status light on the switch just show up/down and speed. Nothing interesting.
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I accept that the 3com switch probably has some code to prevent one port connected to another port on itself. But it does so without regards to VLAN. Annoying, but so it goes.
The CLI of that switch sucks. It sucks *hard*. It's not a "real" cli, but a menu driven text navigation. I hated these things back in the day.
This switch doesn't have a log.
It almost certainly does, you just haven't found it yet.
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Ah ha! The game begins. Easter egg hunt begins.
(Thanks for the heads up. It is worth looking for. Hope I find it on the GUI - last time I did telnet, I think it was back when Emperor Augustus was still in charge of Rome.)
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Can you, with the patch cable disconnected, ping a VLAN4 host from another VLAN4 host at the same time as you are pinging a VLAN2 host from another VLAN2 host? Set up a continuous ping as described above and then connect the patch cable - what happens?
Are you using the same ip schema on both VLANs? If you're not, ping won't work, you can expect to get errors when you ping with the actual error depending on the configuration of the network AND the hosts.
Before path cable insertion:
VLAN2 (main) can ping other machines on VLAN2 (main) but not machines VLAN4 (test).
VLAN4 (test) can ping machines on VLAN4 (test) but not machines on VLAN2 (main).
They are all doing ping with -t, so it just runs continuously. Once patch cable is inserted, no change, as if it wasn't there.
On the other hand, when VLAN4 (test) machines are on the side switch, VLAN2 and side-switch (test) machines can ping each other no problem as expected. Machines on the side are fix-IP for this test (since unplug and re-plug will cause a PC to do DHCP again, those on the side are not getting DHCP). All machines are 192.168.4.x with 255.255.255.0 mask.
I wasn't aware that STP doesn't distinguish between VLANs, but on second thought it makes perfect sense: otherwise, you could bridge two VLANs using OP's method on two different switches and there would be a loop until one of the switches disables the port.
Another vote for "disable STP".