[78863.884179] usb 1-2: USB disconnect, device number 6
[78878.875825] meson6-dwmac fdc00000.ethernet eth0: Link is Up - 100Mbps/Full - flow control off
[78878.875831] stmmac: Energy-Efficient Ethernet intentionally disabled
[79039.038177] meson6-dwmac fdc00000.ethernet eth0: Link is Down
[79039.038182] stmmac: Energy-Efficient Ethernet intentionally disabled
[79042.158269] meson6-dwmac fdc00000.ethernet eth0: Link is Up - 1Gbps/Full - flow control rx/tx
[79042.158275] stmmac: Energy-Efficient Ethernet intentionally disabled
Yes, that is when Iw as testing 100meg forced. Further up is autonegotiate connected to the wall jack:
[76488.925924] meson6-dwmac fdc00000.ethernet eth0: Link is Up - 100Mbps/Full - flow control off
[76488.925930] stmmac: Energy-Efficient Ethernet intentionally disabled
[77337.576339] meson6-dwmac fdc00000.ethernet eth0: Link is Down
[77337.576345] stmmac: Energy-Efficient Ethernet intentionally disabled
[77343.816405] meson6-dwmac fdc00000.ethernet eth0: Link is Up - 100Mbps/Full - flow control off
[77343.816411] stmmac: Energy-Efficient Ethernet intentionally disabled
FYI, I reconnected my Vero 4K+ like before and see this:
[ 136.355375] stmmac: Energy-Efficient Ethernet intentionally disabled
[ 141.555219] meson6-dwmac c9410000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx
[ 141.555226] stmmac: Energy-Efficient Ethernet intentionally disabled
I am not saying that is the issue but just for comparison purposes.
Attempting to keep bad information from propagating.
The longer story here is that I pulled a Cat5e cable years ago to this area but in doing so I broke one of the wires which supports 1G somewhere
There is no āone wireā that supports 1G.
It is 4 usable wires
Not good enough, it must 2 usable twisted pairs, for 10, 100 and 1000mbps.
I would just pick two of the good pairs and rewire it to a two pair jack so it doesnāt ever try connecting at gigabit in the first place.
So you have three usable pairs (blue, orange, and green) and one dead pair (brown)?
Depending on the quality of the wiring you may be able to still pull 1Gbps.
Only two pair (1&2 and 3&6) are used for data transfer, even at gigabit speeds.
The 4&5 pair are generally used to provide PoE if necessary.
Fair points and a poor choice of words on my part.
I fully understand this, the need for twisted pairs etc.
It was close to 10 years ago when I tested this cable and itās been running fine since and works fine with the Netgear switch as a speed converter. However, it is worth be rechecking it. Iāll confirm the pairing, which wire is broken etc. It is possible I split a pair here but I am pretty sure I didnāt. I remember working on this for a few hours.
If need be I can cut a patch cord and repin the cut ends with new connectors and confirmed good pairs fr TX / RX and see what happens. This will be easier and quicker to confirm vs. reterminating the patch panel and wall jacks, both of which are a little harder to get to. Of course if I did split a pair then Iāll need to reterminate things.
Iām not sure where you got this information about gigabit only using two wire pairs or the other two pairs being used except for POE. Fast ethernet uses single transmit and receive pairs but Iāve never read about any gigabit ethernet that does the same. Additionally, although there was some setups with fast ethernet where unused wires were used as a simple way to do basic power transmission that only needed direct connection to a PSU this is absolutely not the way 802.3af/at/bt work as they use the voltage differential signaling as a way that they can just increase the voltage on the pairs without interfering with the signals transmitting over them.
I stand corrected. Although Iāve seen gigabit connections in practice without all 4 pairs working, it is the spec.
Iāve also seen working 10base-T operating with cables without 2 working pairs.
Not that either case might have produced full rated performance, but does show how resilient twisted-pair ethernet is.
Thank you!
Sometimes the simplest solution is best. After thinking about this a bit more I decided to take a patch cord and cut the white/blue and white/brown pairs making it truly a 100 Base T connection to the Vero V from the wall jack.
the dmesg output now shows flow control
[ 12.601611] meson6-dwmac fdc00000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx
and the Ethernet interface has stayed up solid for 2+ hrs, Iāll continue to monitor but this looks like the quick and dirty answer.
I appreciate all of the dialog and suggestions yesterday on this issue. Itās kind of fun to occasionally deal with a physical layer issue vs. many of the software related issue we often encounter.
In the end your suggestion was the correct one in that it was the additional 3 connected wires that were causing the issue. One day Iāll get curious and spend a few hours trying to figure out which wire is broken.
Glad to hear you found a workaround solution.
Iām curious which standard you were using T-568A or T-568B?
You mentioned cutting the blue pair and the brown pair and with both standards that is 4/5 and 7/8 so that didnāt help me narrow down which standard you started with.
NOTE: For those who may be interested, I am a low voltage and fiber technician and I have noticed that many people use the T-568B standard now more than ever. I go into a lot of new builds and find all the cat5e and cat6 terminated with T-568B. I always use T-568A and train others to as well for one simple reason: many men are color blind, especially with blues and greens. If you use the T-568A standard then the 4/5 blue pair is flanked by the 3/6 orange pair and this is much easier for those who are color blind (I am not). It always amazes me how many men I come across that suffer from color blindness and they donāt even know they do. Most lines I test that fail are because people are using the T-568B standard and mixing their blue and greens in various ways. So I am trying to bring about a T-568A standard revival for all those color blind men out there! You may want to consider doing so as well next time you terminate ethernet.
For those who maybe reading this and donāt know these standards off the top of their heads:
Not easily. Itās about a 75 ft run in walls and through floor joists where the holes werenāt quite large enough in spots for all the cat 5e cable I pulled through them. I was fine on the first pull but on the last pull I pulled through 3 more runs and it was tight. I will retest it at some point. It is possible I have a bad jack in the patch panel or a bad keystone jack in the wall plate but I am pretty sure I checked that 10 years ago when I did this wiring.
Ah, itās not something you want to do twice, maybe an external run, doesnt need to be shielded I had a 30m cat5e cable run outside to a poe camera and it was fine, not underneath anything either.
