Problem in Cable installation

Problem in the wall. Pull the plates off and reterminate the cables onto the jacks. Overwhelmingly likely to be a miswire on one of the jacks. Next runner up most likely cause is that the cables you think are connected in the wall are actually going someplace else. But since you imply you get a link light on the computer, you probably have a miswire.

--Dale

You've obviously got a cable problem somewhere. You've got two patch cables and one wired between the jacks. First verify both patch cables, you've already done one. Then check the cable between jacks. Is there another one you can try? Check continuity and also that the pairing is correct. Also, make sure the jacks are OK. Problems with them are rare, but I've occasionally seen ones, where one of the gold wires was not in the proper position.

If you can get your hands on one, a cable tester will help.

Back in the day before I had a budget for tools (and inhereted a crappy infrastructure) I got a lot of use out of a 100 ft ethernet patch cord. It was long enough for me to backhaul from the PC any office to, in my case, the equipment closet patch panel, or even a server.

One of these will let you do an end-to-end test, skipping alll the existing parts.

If you get one take care of it. Get a plastic thingy used to coil up power extension cords. Don't kink or step on it.

Are you *absolutely* certain that *both* ends are 568A. If one end of the cable is terminated 568A and the other end is terminated 568B then you effectively wind up with a crossover cable and not a straight through cable.

By the termination, I'm not talking about the cable, I'm talking about the jacks. There is no such thing as 568A or 568B cable. Cable is cable, It can be rated to be compatible with the 568 wiring specification, but the cable isn't 568A or 568B. What *is* important are the terminations (jacks) at each end. It's the way the cable is terminated that determines if it is 568A or 568B.

You can buy jacks that are 568A and you can buy jacks that are 568B. As long as you pick one kind and just one kind and stick with it, all will be fine. Start mixing 568A and 568B and you'll start having these problems.

And I'll bet that eventually you end up with a 169.154.x.x IP address, don't you?

That's APIPA. Automatic Private IP Addressing. When a Microsoft box can't get an IP address from a DHCP server it turns to APIPA to randomly assign a class B address by default.

So we've just eliminated the PC as a source of the trouble.

I'm betting that you have a wiring problem between the jacks and patch panel.

John

Hi guys!

I'm going to buy a cable tester (IC network) and check the wiremap tomorrow. Since I dont have a cable tester at this moment.

I'll post a complete test results by tomorrow.

regards

Excellent idea!

I'd also make up a second one that is a crossover cable. Use a completely different colored cable (like red or purple) so that you know right away that this is the crossover cable.

John

Hi!

The computer side jack is a Leviton RJ45 jack. They have color coding for both 568A and B on the same block. I've used the 568A

The actual cable is 568A CAT 6 UTP cable.

On the router side I used a LCT or ICT (I'm not sure 100%) terminal block (four points in a block) the problem is there is no color marking on the pin layout. But it gives a BIX block type connector from 1 to 8 from left to right when u keep the clip side down. I've used the same pin color combination as the other side.

U r right when i was trying different cable combinations on both jacks, at one point I got the IP address as u suggested. I' was thrilled thinking it is atlast started to work. But on the switch side no indication for a connection!!!

Regards

Shankar

There's no such thing as 568A cable. 568A or B only specifies how a cable is connected. You'd use the exact same cable for either.

Guys,

Before you dig yourselves into a deeper hole regarding cable and if they are 568A or 568B, you need to understand that cables marked as

568A or 568B meet the transmission requirements published in that standard. You are confusing the standard with the wiring pattern. Check out this link I selected at random where it talks about applicable standards...

Rodgers Platt

And what would the difference be between cables marked 568A or 568B??? Don't confuse marketing with specifications. Manufactures will often sell something for a specific use and use commonly misused terms to describe it. For example, how many times have you seen reference to "DB-9" serial port connectors, even though there's no such animal? (the proper term is DE-9)

The cable has to meet CAT 5 specs, no matter how it's wired. The wiring should comply with 568A or B, though it's not necessary for proper operation, so long as proper pairing is maintained.

We're I've seen this type of error, it usually indicates a wiring problem. Typically it's a split-pair (WH/BL with GR/WH, WH/GN with BL/WH) or a reversed pair (WH/BL pair swapped with the WH/GN pair). Since you mentioned on end is a Leviton that is label, and the other is unlabeled, I would only make changes at the leviton end as you can see what you've done. It start with swapping the WH/GN and WH/OR pairs to fix a 568A-at-one-end-568B-at-the-other problem (a cross-over patch cord at one end would also be a simple test before changing termination). With the link light at only one end, lends me to think that it's a split pair, and with the one end not having any indication for termination pattern, you may have to wait for your tester to trouble shoot further.

Justin

James,

You are still confusing the wiring pattern with the transmission specifications. Each version of the standard, from the original 568 through all the TSBs and addendums up through 568B has had a set of transmission specifications cable manufacturers must meet in order for the cable to be rated as Cat 3, Cat 4, Cat 5, Cat 5(e), Cat 6 and so on. The manufacturers are now stamping their cables with the version of the 568 standard they are compliant with. Thus, a cable stamped as meeting the 568B specs has better transmission charcteristics than a cable marked as 568 or 568A.

You keep referring to the wiring pattern as 568A and 568B and then hold out the reference to a DB-9 serial port connector when the "proper" term is DE-9. Well, the proper term for the wiring pattern used on jacks and plugs is T568A or T568B, not 568A or 568B which denotes the ANSI/TIA/EIA standard.

Rodgers Platt