Weird connection issues or random delays... Check ethernet cable.

[petergebruers 1,261]

About 2 months ago I started noticing occasional 10 s delays on my IP network - not Z-Wave related... My MacBook would occasionally complain about a failed Time Machine backup and I noticed (by click alt-wifi icon to see BSSID) my laptop switched between my 2 access points - sometimes. So I suspected my internet provider updated the firmware of my AP and main router and of course I always assume it is the fault of my provider - LOL. It wasn't.

 

I looked at the port statistics of my managed ethernet switch and noticed... Connection to my AP via 30 meter (cheap) cable was 100 Mbit instead of gigabit... Nothing special in the stats but surely that should have been gigabit speed.

 

I don't own a real network tester but this poor man's tool can help: ohmmeter and measure "loop resistance" of the pairs

 

Pair 1: 22 ohm

Pair 2: 22 ohm

Pair 3: 22 ohm

Pair 4: 25 ohm

 

Ah... Crimp on new connectors and all four pairs measure 21 ohm now. Problem solved.

 

A possible explanation is that one of the connections was poor to begin with and by unplugging/plugging repeatedly I might have made contact resistance worse. Another explanation is that this cheap cable is made of aluminium (it is not even copper cladded) and it does not mate well with the contacts, or may form oxides over time, this cable has been in place for more than 10 years.

[Tony270570 92]

Thank you @petergebruers for your return of experience. 

Nothing really similar but i'll also share mine regarding network troubles. Less than 2 months ago, my hc2 starts loosing my satel connection, or more precisely stops having satel devices feedback, as i was still hable to see the satel connected into the hc2 plugin and the satel was still visible from my network. 

 I 've tested my satel, and my hc2 cables  and didn't found anything special, they were ok. I tryed to desable some scenes thinking that one of them might kill the satel plugin, uninstall some plugins that were installed but nothing fixes. Satel was visible for some minutes sometimes hours and even 1 day. But the problem was coming back again and again and only a reboot was fixing the issue until next crash... I became mad during more than a week maybe two this issue was coming back, and I've got a large satel network integrated in my hc2, meaning that nothing was working as expected... NERVOUS BREAKDOWN !!! I've rase a ticket but never had any feedback , well i was alone facing this issue. 

I've tried everything i can think about but no success, I reboot my satel, nothing changes !!! I change my switch by an old one, stil the same  well I finish by rebooting my DHCP which is managed by a specific device, and ... it fixes the problem !!!

My network was the faulty one like your weird cable... Ok this micro cuts in communication shouldn't drop down my the satel plugin but they were  the cause of the plugin crash. I'm now rebooting my DHCP ones a week to avoid such kinds of issues. 

I've had already notice long time ago that sometimes my internet networks was starting slowing down and the wifi router which is also doing dhcp  after a reboot fixes my connection slow down,  it was really occcasional and I didn't made immediately the link with the HC2/satel issue i had...

Thank you google wifi, one day or another i'll whange it by something more robust.

. 

[petergebruers 1,261]

@Tony270570 interesting story and I think it shows how much faith we put in ethernet and WiFi. And if we would count the number of packets/transactions or number of bytes transferred per "issue" we'd be surprised at the reliability (in a positive way). That puts DHCP or router firmware or cables very low on the list of possible problems. From time to time some suffer from duplicate IP for example. Now you mention "google wifi" and I don't know much about mesh technology used with wifi. But some time ago I did a little research and was surprised to learn about some of the (weird) tricks they use. If I remember correctly, for example, generally speaking the 2.4 GHz received signal is higher than 5 GHz so a client my prefer the crowded and possibly inferior "old" band. So some routers seem to implement a trick, the deliberately make the 2.4 Ghz connection fail with some clients, to force them to (re)connect to the 5 GHz band instead. Sounds clever, but also scary, I think...