Cat 5 Home Network Problem

Under my house I have recently installed a Cat 5 cable. At one end it has a RJ45 wall plate in the room where the ROUTER/MODEM is installed and is connected to this router via a Cat 5 PATCH CABLE.

The other end of the UNDER-HOUSE CABLE is connected to second RJ45 wall plate in another room. Here, this connects (via PATCH CABLE) to a network PRINTER (static IP), thus connecting the printer in one room all the way back to the router in another room. Here's a schematic:

ROUTER/MODEM-->PATCH CABLE #1-->RJ45#1-->UNDER-HOUSE CABLE-->RJ45#2-->PATCH CABLE#2-->PRINTER

Simple, right? And works well with the printer. All the computers (Win 7, Win 10, XP) on the network can see the printer and use it.

BUT I tried to plug in a lappy at RJ45#2 and it complains that the network cable is (remains) unplugged! i.e. it can't establish any kind of connection to the router even though the printer can.

The lappy can connect via PATCH CABLE 1# so it seems there is a problem with the UNDER-HOUSE CABLE and/or its RJ45 connections. BUT BUT the printer connects!

The only other clue is that, yes the printer connects , but it doesn't show on the modem's list of connections while every other device does.

What should I be looking for when trouble shooting?

Thanks in advance.

 

First, was it really CAT-5?

Typically, when pulling new Ethernet cable, you should always use the latest industry-wide technologies - that would be CAT-6. If not using CAT-6, then at the very least, CAT5e. Category 5 cabling (CAT-5) is a much older type of network cable designed for "theoretical" speeds of 10Mbps and 100Mbps.

CAT-5e is a significant improvement ("e" = enhanced) over CAT-5 because (1) it supports 1000Mbps (1Gbps). And (2) CAT-5e is designed to eliminate or at least greatly attenuate "crosstalk" interference - interference that occurs between the wires inside the cable that can greatly impact networking performance and speeds.

CAT-6 is designed for even greater crosstalk suppression and 10Gbps network speeds. CAT-6 is generally considered overkill for most home and small office networks - for now. But for future proofing, when everything will be networked and streamed throughout homes, CAT-6 is typically installed.

Several things. If me, I would probably re-terminate (put new connectors on) both ends. Printers don't require or use high-speeds. A 10Mbps network is find for printers. Most computers these days support at least 100Mbps and to achieve that, even with the best of cables, proper termination is a MUST.

So to that, did you invest in a good quality crimper? I wasted money on two cheap crimpers before I finally gave up and bought a quality $40 (15 years ago) crimper. While, in effect, that $40 quality crimper cost me $80 (counting the $40 I wasted on the two cheap ones) it paid off in the end by not wasting connectors, time, and of course, maintaining lower blood pressure levels. I almost always distrust people who say, "trust me". But trust me on this. If you make your own Ethernet cables (and I think everyone should) invest in quality tools.

You should also invest in a network cable tester. Fortunately, you don't have to spend a fortune on them and they can save a whole lot of frustration and slow down hair loss, graying, and hairline recessions!

Other things to look for are no crimps or bends in the cable runs. If you have to make any turns, make sure the cables gracefully curve around the corners. Make sure the cables don't run parallel next to any other electrical cables. If you have to cross over any other cables, try to do so at 90°. Make sure the cables are loose - that is, not pulled taut as that can stretch the insulation, degrade continuity at the crimping point, and change the twist angle of the TP (twisted pair).

Also, while Ethernet cables can "technically" be up to 100M (328 feet), in practice, they should be as short as possible. If you are going from one end of the house to the other, it may be necessary to put an Ethernet switch near the 1/2 way point.

And note that rodents and some insects have been known to chew on cable insulation.

 

Thanks Digerati, Lots for me to think about here.
Cheers

 

Keep us posted.

 

Disable and enable the network card on the lappy - will it get an IP / Internet?
Is the lappy static IP'd? What is you give the lappy the printer's IP, then does it work?
What is your subnet mask? 255.255.255.0 or ??
If the last octet is higher the 0, say 248 - you can only have 6 hosts - maybe your DHCP pool if full - just tossing that out there as an example.
If you have a multimeter you can short the connections and do a continuity test.

 

UPDATE: Situation seems to be resolved. The female wall plug at the router end had some loose wires. On top I reset all wires on both female RJ45 for good measure. So far so good!

 

I note the same logic applies about using quality wall Ethernet connectors as it does for crimpers. Investing in quality pays off in the long run. Of course, a good trip over a cable can yank apart any connection. This is where a decent tester can come in handy too.

I am glad you got it sorted out and thanks for posting your follow up.