Hello,
have RB4011 at home for about 3 years. Last days I found there is a problem with flapping ethernet 5 port.
Ether5 is down for 2-3 seconds and back up at random times between 30-60 min. eth2-10 are in bridge
What I tried to do:
change old FTP (indoor) cable to to new one FTP indoor cable (cat5e)
reboot rb4011
connect cable from eth5 to eth4 (so eth4 started to flap)
Have the latest rOS 7.15.3 with the same version of firmware (7.15.3).
Do you have any idea what can I do please?
Thank you.
There was simple unmanaged TP-Link switch connected to eth5. From switch were devices connected.
I replaced that switch for RB750Gr3 and from that time there is no ether5 down/up so it’s stable now.
So you think the switch is damaged? It was connected to eth5 for months without any problem.
That or something else on the network that the unmanaged switch allows through but the 750GR3 intercepts/blocks, hard to say.
How many ports has the TP-LINK switch?
Try changing them around, it is entirely possible that only one port of the switch is defective.
Anecdotally I have in use a no-name unmanaged switch (8 ports) that years ago (probably) got zapped by a mains surge or lightning return from ground or whatever.
One port was dead.
Another port (not physically near the dead one) was flapping.
I simply put a couple of RJ45 “corks” on those two ports and used it (and still use it) as a 6 port switch.
It’s 5-port TP-Link switch. Forgot to say I replaced it for another 5-port TPlink, same result.
Anyway from the time I replaced switch for RB, there are no problems.
It’s really strange
Since the replacement with a similar device didn’t change result (I doubt that two devices can be defective in exactly the same manner), it is actually possible the the RB750GR3 “filters” some activity on the network that ultimately causes the flapping issue.
I would exclude that a commonTP-LINK 5 port switch creates the issue in itself, AFAIK these are as plain as they can be.
You can try however to put the RB750GR3 “in series” with one of those switches and see what happens.
I.e:
RB4011(ether5)<->RB750GR3<->TP-LINK<->other network devices
