Have asked our own partime internal guy (small firm) but he’s on a different site and so far has been of ashtray/motorbike usefulness.

We have a small work network with ca. 10 devices attached to it – PC’s, a central scanner / copier thing, a piece of lab equipment that has a small microprocessor attached for data recording, etc.

All these are connected up by wall access points, cabled into a ‘Hellermann Tyton’ Megaband port array (I think it’s called a patch panel). The ports from these are cabled in to a Gigabit switch, which in turn is cabled to a router and onto the outside world.

Except the outside world is so slow all of a sudden.

I’ve tried connecting the router cable to a different port, no difference. But if i disconnect the router from the GB switch and then connect it directly to a PC (ie: not splitting it through the Gigabit switch) then it gets superfast again.

Is there any reason why a GB switch would ‘suddenly’ start behaving like the e-version of a lake of treacle. Is it worth trying to get a new one and see if it improves it. I’ve tried one by one disconnecting all the cables from the GB switch to the patch panel and that doesn’t change anything so I don’t think that one of those connections suddenly became the critical factor.

Any ideas what to try next?

(and yes, the IT guy did suggest turning it off and on again)

Plugged anything new in lately?

Unplug it.

As above, anything that is plugged in has been disconnected again one by one to see if that isolates the problem

I was going to suggest a direct test to the outside world by connecting a PC directly to the router and running something like a speedtest- but you’ve done that.

Check and see what speed and duplex the “router” switchport and the router itself are connecting up as.

Running a speedtest directly to the router got me about 17MB/s (units might be wrong, but 17)

Running a speedtest with PC-switch-panel-router – and it won’t even run, get a ‘page unresponsive, kill or wait’ from chrome.

Did you do the turning off and on again thing? Our Netgear firewall falls over in hot weather and we have to reboot the network about once a month. Dropbox gives the clue that things have gone wrong as the icons grey out (on Macs).

If it’s an unmanaged switch I’d suggest you’ve done pretty much everything you could do to narrow it to the switch. What’s your internet connection speed (i.e. how much are you expecting to be able to push through it in normal ops)? Even 10Mbps half duplex link would be adequate for mine for example so you need an idea of scale.(EDIT just seen that 17Mbps figure – 100Full would be more than adequate).
Could be a crappy patch cable somewhere on the path, including cabine to wall point – make that path as simple as possible with known good ideally new cables.
10/100 switch is buttons, 1Gbps not much more and probably available in PC World – you might save a bunch of time just grabbing one – 24+ ports though might need mail order or a bigger specialist.

If its an asymmetric internet connection, seen a lot recently of uploads killing the connection as the ACKs and handshakes can’t squeeze up the pipe, but disconnecting everything one by one should isolate .. likely to be a wireless access point with someone syncing up Google Photos or something.

HTH

Running a speedtest directly to the router got me about 17MB/s (units might be wrong, but 17)

Running a speedtest with PC-switch-panel-router – and it won’t even run, get a ‘page unresponsive, kill or wait’ from chrome.

[edit – there’s an example; took so lon to load the post i got another ‘kill or wait’ error, reposted, now find I’ve posted it twice]

Let me get this right…

PC to Network to Router = slow

PC to Router bypassing Network = fast

Is this internet or just general speed? I’d be guessing internet first.

Walk round Office and see who is on YouTube or Torrenting 5 series of Game of Thrones – they’re probably the one getting annoyed as their download keeps getting interrupted by some berk unplugging stuff 🙂

Joking aside, I would initially be checking what data use is happening on your broadband.

If it’s ADSL, is someone uploading and they’ve flooded the upload? You only get a small upload and maxing it out halts the download – so if Harry the Web Guru has just been putting some new high res images of the office online, give him a slap.

I did see one site where to save money the phone supplier plugged an IP phone between the PC and wallport as a passthrough. The phones only worked 10/100 so the Gigabit switch suddely became a bit useless.

If it’s not internet then it can get tricky to troubleshoot if it’s a fault, misconfigure or other problem. In the absence of anything changing as well it’s difficult as that’s the usual cause.

If the router is OK direct on your PC then the other thing you may have done is prove that the rest of the network is where the problem is.

Could be a crappy patch cable somewhere on the path, including cabine to wall point – make that path as simple as possible with known good ideally new cables.

Wouldn’t disconnecting those cables one by one isolate that?

Similar to suggestions above, have you tried bypassing the patch panel.?
When you went straight to the router did you try 1 PC to the router through the switch but skipping the patch panel.?
If the switch isn’t the cause of the slowdown then it sounds like you have a damaged cable somewhere that is likely causing the slowdown.

All of the above assumes of course that there isn’t a person or device on your network that is flooding the connection for some reason. Have you tried restarting/unplugging and replugging every device connected to the network..?

or device on your network that is flooding the connection for some reason

Using windbg, paused floods the LAN once the network cards own buffer is filled up. Took us a while to find that one!

one thing to check. is the machines network card actually showing its own connection as being gigabit when connected the slow way?

Summink backing up a million photos to da cloud (upload)
Or having hacked you, some foreign miscreant uploading the contents of your megacorp (upload)

Might be worth trying to get on the router or on the ISP ‘account’ page to see if there’s a lot of data being/been transferred. As another correspondent said if it’s ADSL (which means lots downloads, not lots uploads – A = asynchronous) then anyone uploading anything significant will kill the whole experience.

But again – and apologies if I’m misunderstanding, I’m not an IT guy, just someone doing what to me seems like logical stuff.

If I unplug the devices from the Gigabit switch, then whoever’s stealing all the space then won’t be. And the problem would go away, correct? But it didn’t.

apologies if I’m misunderstanding, I’m not an IT guy, just someone doing what to me seems like logical stuff.

If I unplug the devices from the Gigabit switch, then whoever’s stealing all the space then won’t be. And the problem would go away, correct? But it didn’t.

Nah, you’re doing fine.

Can you confirm that it’s just Internet traffic and not all network traffic?

If you disconnect everything bar yourself and the router from the switch it’s slow, but direct into the router it’s fast?

Is the router connection to the switch Gigabit (at both ends)?

Make and model of the switch / router may help.

(You have switched the switch off and on again, yes?)

If I unplug the devices from the Gigabit switch, then whoever’s stealing all the space then won’t be. And the problem would go away, correct? But it didn’t.

Apologies from me, I kind of assumed you done them one at a time and not all at once. Cougar’s questions next.

(-:

Essentially with this sort of problem the challenge is that you’ve got a lot of variables, or “could be” causes. The way to diagnose it (in the absence of the ability to run diagnostic tools directly) is to start narrowing it down and ruling things out until you’ve pinpointed it. (Which is exactly what the OP’s doing.)

Sorry haven’t got time to go through the other posts so appologies.

This is a good place to start:

Check and see what speed and duplex the “router” switchport and the router itself are connecting up as.

I would test direct to a PC. If the speed good. Then Connect just that PC and the Internet router to the Switch and test.

If all good then great.

Also, have you rebooted the Internet router. My ADSL at home gets it’s nickers in a twist from time to time.

Then add each device and keep testing.

If it suddenly gets slow after adding a certain device then you know it’s that device.

If you are on one flat network, all devices in the same vlan/subnet and you have a NIC on a PC crapping itself it will broadcast to all devices on the network.

My biggest advice, add devices one by one and check speeds after each one.

If I unplug the devices from the Gigabit switch, then whoever’s stealing all the space then won’t be. And the problem would go away, correct? But it didn’t.

Agreed, hence why I said I think your blaming of the switch may well be on target – it wasn’t clear (to me at least) that all devices were unplugged leaving only router and test PC on the path through the switch.

Same with patch chords – I saw someone do something similar but when they isolated router and PC they used a different patch chord to the path through the switch.

Duplex mismatch issues are unlikely to be the cause as auto neg has been part of the Gb standard for years and an unmanaged switch is unlikely to brain fart into an incorrect setting (its usually set wrong by and admin), but it’s still and outside possiblity – that would most likely mean a new switch anyway.

Where are you? The community here might have a Gb switch to lend you for 10 minutes?

Are your cables the right way round? One way is faster than the other, you know.

..but seriously, have you tried turning the router and the switch off and on? I know it sounds like a lame get out clause but it’s the first thing to try.

You sound like you’re on the right track.

Duplex mismatch issues are unlikely to be the cause as auto neg has been part of the Gb standard for years

That’s why I was asking whether it was G/E at both ends.