Hello Folks!
After upgrading router os and firmware the ethernet port stopped responding.
I have now two devices who got the same symtom, eventually tree.
In all cases there is no sign of degradation or link drops/errors, they connect 100Mbit/s full duplex.
Upgrading RoS to next version in number series or to bug fix or latest stable immediate leads to problems with ether1.
RB411, yes and good old one but we have plenty of them in production.
Cannot be upgraded from RoS5.20, any attempt doing so and ether1 stops working completely.
RoS5.21 makes ether1 not working, no link ever comes up whatever you do, like replacing PoE injector or even power it via DC jack directly.
However, customer is happy since years back and speed is pumping around 20-25Mbit/s through the device which is located some 500M from base station.
Device was never replaced and still is there today, but can not be upgraded.
RB711-5HnD, worked for many years and was successfully updated many tomes to latest stable, with a happy customers.
Is stable with all router os till version RoS6.37.5 and firmware 3.33, any attempt upgrading to newer versions by time of writing makes ether1 go down and up all the time.
If upgrading to latest bugfix or stable, a cable test indicates that tp pair 3 is open after 18 meters most of time, but also other distances reports, and sometimes it reports short circuit at same or another distance. The interface goes up and down all the time.
Reported distances varies between 10-25 meter.
Not upgrading the device and customer is still customer happy and the device pumping around 20-30Mbit/s to basestation located some 800M from basestation.
But this device has another oddity, if trying to connect it to another home user router (d-link, linksys, …) and you never got any link at all on ether1.
Connecting it to RB751U-2HnD, and you immediate got 100Mbit/s full duplex link, thats say, if not trying to upgrade RB711-5HnD because then ether1 immediate fails.
In all situations we have replaced the PoE injector, connected a cable test and all was fine.
I admit the devices are old, but we have plenty of them in production.
What can this be, anyone who have seen this from before ?