21m cat5E cable not working with new fibre router (still works with copper router)

[#1]

I have just upgraded from copper BB to fibre both with PlusNet. New Hub One router replaces old PlusNet router. Wifi working fine at 32Mbs and short ethernet cables work fine, but existing 21m cat5e cable not recognised with new router (worked fine for 3+ years with old router). If I set up old router that ethernet cable then recognised again. I am using my laptop to test this.

I have tried all ethernet sockets on new router, no difference.

Short ethernet cable works.

Long one works with old router but not with new......this is the problem.

Have contacted tech support and they say long cable must be not compatible with fibre - its Cat5e and I have re-made the plugs on both ends and re-checked with basic test (lights) tool, and it still works with old router (altho no internet connection as its a copper router). I am not aware that there are different specs for ethernet cables for fibre.

Do I need to replace the long ethernet cable and if so, with what please? Its a pain as its fitted into the eaves around the house. I note that a longer cable of same spec worked fine in old house on BT fibre router.

many thanks

[#2]

@kspanner  I suspect the problem is that the fibre router (I assume it's a Plusnet Hub one) has gigabit ethernet ports whereas your old router only had 100m ports. Sometimes long cables wont work at gigabit speeds , especially if they're stranded cable. You could try setting your laptop port to 100m ( if that's possible) to confirm if that's the problem. The hub one port should then negotiate down to a 100m connection and work.

[#3]

Gigabit ethernet is rather more sensitive than the old fast ethernet.

I would buy a prepared 20m cat5E cable (with plugs pre-done) - if you need more than 20m then longer lengths are available...

[#4]

Quick and dirty fix.

Turn off WiFi and DHCP on the old router. Connect one of the Ethernet ports on the old router to the new router with a short Ethernet cable. Connect long Ethernet cable to another port on the old router. Test.

If that works, then one option is simply to carry on with that solution. Another would be to buy a cheap Ethernet switch (£12-£15) to put in place of the old router.

It sounds as if the Ethernet switch in the new router is not working as it should. Cat5e has a length limit of 50M at 1000mbps ( I think!). It could be you have a faulty router. 

[#5]

A new piece of Cat5E (Gigabit) ethernet cable with pre-wired plugs will cost about £10 for 20m.

[#6]

Thanks for the input.

i have looked to reduce my network adapter speed to 100 on my laptop and cannot, thank you.

I would buy a pre made ethernet cable, however it runs outside on the eaves (shortest route) and has to penetrate a window frame at each end to enter house. I dont want to drill holes for the plugs, rather large.

Whilst it could be my plug crimping, i have re-made them and also the ones i crimped at other house worked fine with fibre (BT).

I am wondering whether to simply replace the long ethernet cable with cat 6, would that solve the problem?

[#7]

and just to add, I wondered if it was a faulty router, Plusnet support say its not and would not send a replacement.

[#8]

@kspanner  have you tried @wisty s suggestion with the old router ?

Nb although you may also need to change the ip address of the old router to avoid a clash with the hub one. I suggest 192.168.5.1 as that should be outside the default dhcp range of the hub one

[#9]

I am afraid old router use alongside new one suggestion beyond my capabilities, sorry.

[#10]

@kspanner 

The PlusNet supplied router is "basic" - it is in fact a re-badged BT HH5

You could look to get a BT HH6 or even the newer SmartHub2 off eBay - they work on PlusNet. There are setup guides available on this forum. Just make sure you get the FTTC version if you choose this route.

PlusNet will work with any VDSL router so there are other options.

Brian

[#11]

@kspanner  if you can confirm what model your old router is , then I'm sure we can give you step by step instructions on how to do it.

[#12]

@kspanner 

Expanding on the post by @wisty  if you turn your old Hub Zero into an Access Point, see  https://community.plus.net/t5/My-Router/Turning-a-Hub-Zero-into-an-Access-Point/m-p/1687008#M14870 Plus the additional info here. https://community.plus.net/t5/My-Router/Turning-a-Hub-Zero-into-an-Access-Point/m-p/1687061#M14876 and connect this at the far end of the Ethernet cable this would force the long cable to run at 100Mbps. Plugging your computer into another of the Hub Zero LAN sockets would prove if this problem is being caused by the long Ethernet cable being unable to operate at 1Gbps.

[#13]

You must accept that your current external cable is not up to Gigabit speeds and needs replacing with true Cat5E cable. It needn't be Cat6 - but it ought to be suitable for use as an external cable.

[#14]

OK< I have followed all that, I now have the new router connected to the adsl filter at the master phone socket, and the long ethernet cable in a yellow LAN socket. The old router at other end of long ethernet cable plugged into yellow socket. short ethernet cable to PC.

when I switch off wifi laptop sees PC icon with "unidentified network no internet access"

[#15]

baffled by this one; it is true Aat5E as it says so on the grey sheathing. How does one identify suitability for external use?