HELP - Network issues and outside help

[psydii]

...did as someone else suggested worked from the core outwards. Disconnected all links to remote cabs, and slowly added them back in, once it went bonkers again, disconnected that link....

 

This is basically a highly efficient troubleshooting technique called half-splitting. It's great for searching quickly for a thing that exists in within known boundaries. (in computer science this is equivalent to a binary search).

 

It's been a while since I last posted one of the most useful series of articles I have ever read: "Secrets of a SuperGeek: Troubleshooting" by Mike Sullivan published on TechRepublic back in 2000. It covers the half-splitting technique in some practical detail. (The technique was also described in the appendix of at least one official Apple Professional Training book)

 

https://web.archive.org/web/20031028065615/http://techrepublic.com.com/5100-6263-1031759.html

 

https://web.archive.org/web/20031028065615/http://techrepublic.com.com/5100-6263-1031386.html

 

https://web.archive.org/web/20031028065615/http://techrepublic.com.com/5100-6263-1031758.html

 

https://web.archive.org/web/20031011135134/http://techrepublic.com.com/5100-6263-5029507.html

 

The original articles seem to have vanished, last time I posted them here they were at new URLs, but now it seems they are completely expunged from the TechRepublic site, so I've linked to the original urls via the wayback machine.

Edited January 22, 2024 by psydii

[HPlum78]

This basically a highly efficient trouble shooting technique called half-splitting. It's great for searching quickly for a thing that exists in within known boundaries. (in computer science this is equivalent to a binary search).

 

It's been a while since I last posted one of the most useful series of articles I have ever read: "Secrets of a SuperGeek: Troubleshooting" by Mike Sullivan published on TechRepublic back in 2000. It covers the half-splitting technique in some practical details. (The technique was also described in the appendix of at least one official Apple Professional Training book)

 

https://web.archive.org/web/20031028065615/http://techrepublic.com.com/5100-6263-1031759.html

 

https://web.archive.org/web/20031028065615/http://techrepublic.com.com/5100-6263-1031386.html

 

https://web.archive.org/web/20031028065615/http://techrepublic.com.com/5100-6263-1031758.html

 

https://web.archive.org/web/20031011135134/http://techrepublic.com.com/5100-6263-5029507.html

 

The original articles seem to have vanished, last time I posted them here they were at new URLs, but now it seems they are completely expunged from the TechRepublic site, so I've linked to the original articles via the wayback machine.

 

And here is a book that I have mentioned on occasion that is worth reading:

 

How to Find a Wolf in Siberia: or, How to Troubleshoot Almost Anything

https://www.amazon.co.uk/How-Find-Wolf-Siberia-Troubleshoot/dp/1720156409

 

happy fault finding...

[ITGuyNW]

Who would like a conclusion?

 

So the network was up and down all weekend again, with a spike at 12.30 every day.

 

Now whenever the network was having an outage, different switches were going down, or smoothwall wouldn't talk, and any loops in the logs were just pointing at the uplink. So there was a loop or issue somewhere, just not on the switch I was looking at. On Tuesday, it went funny again however this time one of the switches in one particular building was offline. Checked the logs and it was saying a port was up/down constantly. Traced it to... a Yealink Teams phone.

 

Since unplugging it yesterday at midday, I've had full network connectivity, no blips, no alarms, all back to normal.

 

So for some reason, this teams phone, which is only about 6 months old, was flooding the network.

[PotNoodleTech]

So - is access to local LAN services ok - no slowness or dropped packets on network servers file shares etc etc?

 

I.e can you isolate that it is infact external internet issues rather than an internal network loop as others have suggested above.

 

A network loop won't just take out the internet services, it will make everything go wonky from shares to log in and out to printing etc

[3s-gtech]

Traced it to... a Yealink Teams phone.

Yeetlink now.

[simpsonj]

Just out of interest, did the phone have a pass through (so it can pass on the network to a PC)? Was that pass through connected back to the network?