Faulty ethernet switch ?
I have a hard wired ethernet switch to serve my TV and CCTV units. Recently I have been getting a message on the TV screen "LAN cable disconnected". After re booting the router all seems fine until the next time. Yesterday it happened and I noticed the lights on the switch were flashing back and forth at great speed. As a thought I checked to see if I could still use the internet, that was working. I didn't have time to do anything and left for the time being. When I went to see all was steady again. Does this indicate the switch is faulty?Regards I’d check for possible loops on the network, everything flashing can be a sign of this. Or possibly there may be a device flooding the network due to a fault/issue.
When it happens again, try unplugging ports 1-by-1 to see if this stops it. Narrow down the issue.
Or, yes, your switch is knackered Yeah, right OK. Due to the fact I am totally un techy, the first paragraph is double dutch and means nothing to me, sorry." Loops device flooding"????? I should have explained. Second paragraph I can do. My router is upstairs and connected to my two computers, one of which I could disconnect if necessary. One cable runs up in the loft and down to living room to the switch. Two cables from switch go to TV and CCTV. The fact that this time I checked the internet and it was working gave me cause for concern about the switch. When and if it happens again I will check the cables in the switch. I hope it is the switch, much easier. It is one of the "rules" of LAN topology that there must not be multiple paths through the network anywhere - if there are, it can cause data to endlessly circle ("loop") the network filling up all the capacity in the network and effectively creating a massive traffic jam. Hence the advice to - "check there are no loops." It does not sound like you have any and it is unlikely you have created any unless you have changed something recently, but the symptoms you describe sound characteristic of such a problem, hence the advice to check.
Some devices are not terribly good at reporting meaningful error message, so "cable disconnected" can sometimes be mis-reported when the device really means "I cannot get a network connection" which could have multiple causes - such is the price of "dumbing down" things for the domestic market.
Ideally, one would swap the offending cable for a "known good" one and see if the problem goes away.
There is no universal standard for the meaning of the indicator lights on switches; to know for sure what they mean, one would need to read the manual or check the vendor's web site technical support. A common scheme is that on a per port basis, a "solid" (unblinking) light mean the link is connected and blinking means some data is in transit, but this is by no mean universal. Sometimes they use different colours for different things, often the link rate ("speed.")
If the lights are chasing back and forth link a rope light in a disco or KITT's front bumper adornment, that may mean "something" (for example, I've seen some switches that did similar things when you updated their firmware - but that cannot happen "by accident" you have to take deliberate action to do so,) but to be sure, again you need to check the manual.
It is strange that rebooting your router "fixes" the problem, which again might be indicative that there some weird traffic jam going on. It could be that you have a device that has gone bad and is flooding the network with junk (a "jabbering NIC" we used to call them in olden days, but I can't remember when I last saw one) or got some malware and it may not necessarily be the device that complains that is the culprit.
Similar to the advice of MrShabz, one way to check is to physically disconnect everything (including all Wi-Fi devices) and then gradually add back one device at a time over hours/days and see if it narrows down the offending device. Such testing is incredibly time consuming and labourious, and of course you have loads of devices with "no network" whilst conducting such a testing (upsetting domestic harmony) and you may not find anything even then.
It may be politically more expedient to put your hand in your pocket and spend a tenner on a new switch - if it makes no difference, then you know for sure it was not your switch that was culpable and you have wasted ten pounds, but for the price of two KFC's, pints of lager, (insert own value system here) you might judge it is worth it. Hi mickevh, Thanks for that easily understood explanation. Funnily enough it happened again this morning, the envelope on the TV screen indicating that the connection was not sound, I must have missed the message that comes up. I don't do much streaming as they call it; only BBC iPlayer, no films. Anyway I did as advised and removed each connection at the switch and moved the along one port. There wasn't an immediate result but shortly after the light settled down to two. I think you comment about wasting a tenner is absolutely one the money (no pun intended) Its all trial and error after al. Thanks for your in depth explanation, something to put away in the memory bank.
Regards Aye, but do the testing first. Worst case scenario - you buy a new switch, only to find the problem persists.. you then swap cables out, and find one £2.50 cable was buggered.
Though, in that case you end up with a spare switch data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 Yes I keep doing the testing but received a new switch yesterday and the light on the old one were still stream across the switch so changed over. Time will tell and it was only a tenner. Thanks everyone for your input, most appreciated.
Regards
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