Perfectly fine, unbroken cat5e cable not reaching gigabit...

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BrandonG

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Nov 23, 2010
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So as some of you may know, I purchased two gigabit switches and a few NICs' I have a run of cat5e cable going from one switch to the other with a total distance of about 27 feet. Ive run two different cables and still am not getting gigabit. Checked both wires with multimeter, all pairs are unbroken. Used a cable that Ive been using for one of my computers and it got gigabit just fine. Anyone have any clues of what is going on?

Ive ruled out electrical interference by running the cable along the floor away from everything and still got the same results.
 
Put the switches together and connect it with a short patch cable. See what happens then.
 
You checked for continuity, but did you check impedence per pair? How about cross talk? Do you have a fluk MM. Is this a home made cable or a store bought?
 
Are you crimping ends on? Cutting jacks onto the ends?

Did you observe the proper wire order,and keep the pairs together?

Are you using all four pairs?

Did you accidentally make it a crossover cable? Some GigE gear will revert to 100mb when a crossover cable is used.
 
You checked for continuity, but did you check impedence per pair?
All are the same

How about cross talk? Do you have a fluk MM.
a what?

Is this a home made cable or a store bought?
Home made with a spool of cat5e. used it for many other gigabit connections

Are you crimping ends on? Cutting jacks onto the ends?
crimp ends

Did you observe the proper wire order,and keep the pairs together?
yes

Are you using all four pairs?
all four

Did you accidentally make it a crossover cable?
nope
 
Have you tried that cable between one of the NICs and the switch? Which switches are you running between? Have you tried to force gigabit instead of auto negotiate? Anything in the switch logs?
 
/usr/home said:
I'd just buy a premade 30 footer and call it done.
Click to expand...

Fry's or Monoprice. I don't screw with crimping my own cables anymore unless it's either an EXTREMELY long or EXTREMELY short, run. I've got a little 6" patch cable here that I made about a year ago and it's the last one i made, lol.
 
Dont have the money for pre made ones sadly.. Id need a 30' and a 50' (i have two long cable runs that are doing the exact same thing)
 
You already found out that using a short patch cable works fine, so your options are to buy a new cable or try and re-do the one you have now.

Personally I'd just go for a new cable, just in case there is something else wrong with the current cable and its not just the jacks.

ETA: monoprice 5e cables: 30 foot: ~$3.00, 50 foot, ~$4.50. Granted it is 1/4 the price of your switch for $8 worth of cables, but in the grand scheme of things it would be worth it.
 
Your spool is solid-core wire, correct? You probably have a small break in one of the cores (FWIW, a DC voltmeter is going to be useless for testing this kind of thing. You want something that uses an RF test signal (or really fast pulses, like a TDR)) that is causing an impedance mismatch. A DC ohmmeter wouldn't show anything, but at RF, it could be enough so that the ethernet link isn't working (maybe a bunch of power is getting reflected or something).

RF is weird. When in doubt, replace the cable.
 
I dont have a way to test that sadly... but three runs of cable being bad? seems odd since all others worked fine...

Also yes the only things connected to gigabit switches are gigabit
 
Are you using stranded ends on solid-core maybe? Maybe not keeping the twists tight enough right up to the connector?
 
Same pack of ends for all the other cables.
Left the wires twisted as much as possible... I might try making an end tester
 
Have you tried multiple interfaces?

Put a system in place of one of the switches and see if you get gig speeds. If you do put the other switch in its place and see what you get.
 
have you tried forcing the computers/devices plugged into the switches to 1000/full? The auto-negotiation process might be fouled up somewhere.
 
what is the color code you are using ? Have you tried cutting the ends off and re-doing them ? Have you re-crimped the ends put them back in the crimper and crimp them again.
 
have you even tried re-terminating? it takes an extra 90 seconds. i make cables all the time and i still screw one up every once in a while.
 
seems like cable is bad.

if you plug a device into the switch not switch to switch, does it get gigabit?

go to walmart cables are cheap
 
You reversed a pair doing your ends.

I've done this so many times making my own cables it's not funny. Redo the ends and make sure they're identical.
 
Ok, I've been through this myself. It's the cables. Whether a bad crimp or mis-wire, it's the cables.

I swore mine were good too, until I lopped off the ends and re-did them and they finally worked.

BrandonG said:
You checked for continuity, but did you check impedence per pair?
All are the same

How about cross talk? Do you have a fluk MM.
a what?

Is this a home made cable or a store bought?
Home made with a spool of cat5e. used it for many other gigabit connections

Are you crimping ends on? Cutting jacks onto the ends?
crimp ends

Did you observe the proper wire order,and keep the pairs together?
yes

Are you using all four pairs?
all four

Did you accidentally make it a crossover cable?
nope
Click to expand...
 
@shadow Yep, tried the other router and the server.
@Dytralis Everything is at 1000/full..


It seems it has to be something with the cable, but i honestly dont know... When I get the new spool, I will pull out the length I need and put ends on it and see if it works before putting it in the ceiling.
 
Its a surprise no one has mentioned this, ive had trouble with it in the past... where did you get your crimper? I got my first one from radioshack (the $30 jobber that does RJ-45 as well as RJ-11), and it seemed to do a good job until I plugged it in. 3 of 5 cables didn't work, the other two at 100Mbit. It turns out that my crimper didn't have a handle stop. I crimped so hard that the "fingers" on the plug end sank in too far on the connector. They had GREAT connection with the wire, however the plug fingers only made marginal contact with the pins on the switch.

I suggest you reterminate your cable, paying attention to how hard you crimp. You only want the prongs of the fingers inside the connected to bury themselves to the valley, and no more.

Barring user error, there is no reason a personally terminated cable should be any less reliable than a store-bought.
 
I like the ends that allow the wire to pass through the end a bit. It allows you to double-check that you got the wiring correct, and guarantee's every wire is pushed in far enough before crimping. After crimping, you just take a razor and lop off the exposed excess.
 
Thanks fuxxy, that very well could be.. Although my crimper from RS was $40.. But yea, I am quite sure I crimp too hard. Thank you!

@larrry, my ends dont have open faces
 
TechLarry said:
I like the ends that allow the wire to pass through the end a bit. It allows you to double-check that you got the wiring correct, and guarantee's every wire is pushed in far enough before crimping. After crimping, you just take a razor and lop off the exposed excess.
Click to expand...

I hate those end's. I never buy them, but i did just buy a pack of the shielded ends :)

MMMMM orange cables here we come!
 
TechLarry said:
I like the ends that allow the wire to pass through the end a bit. It allows you to double-check that you got the wiring correct, and guarantee's every wire is pushed in far enough before crimping. After crimping, you just take a razor and lop off the exposed excess.
Click to expand...

EZ?
 
so an update on this:

I just purchased a new spool of 500' cat-5e cable from cables to go and made up a ~30 foot cable. I made sure I didn't crimp too hard and etc. Unplugged a cable that was getting gigabit between my main machine and a gigabit switch and plugged my new cable in only to get 100mb/s.

also tried making a 4 foot one and it wont get gigabit either...

Anyone have any idea? if it helps, this is what I got: http://www.cablestogo.com/product.asp?cat_id=3529&sku=27353 (I got blue though)
 
BrandonG said:
so an update on this:

I just purchased a new spool of 500' cat-5e cable from cables to go and made up a ~30 foot cable. I made sure I didn't crimp too hard and etc. Unplugged a cable that was getting gigabit between my main machine and a gigabit switch and plugged my new cable in only to get 100mb/s.

also tried making a 4 foot one and it wont get gigabit either...

Anyone have any idea? if it helps, this is what I got: http://www.cablestogo.com/product.asp?cat_id=3529&sku=27353 (I got blue though)
Click to expand...

what is the color code you are using ? Is it the same as the cable that you are swapping out ?
 
Dytralis said:
have you tried forcing the computers/devices plugged into the switches to 1000/full? The auto-negotiation process might be fouled up somewhere.
Click to expand...

yeah what this guy said. I don't know why but my laptop refuses to do gigabit unless i turn off the Auto-Negotiation and set it to 1000mbit. On that note, have you tried multiple devices?
 
WO O WB B WG G WBr Br


and yes, tried it on two gigabit machines that have gigabit connections with other cables
 
BrandonG said:
WO O WB B WG G WBr Br


and yes, tried it on two gigabit machines that have gigabit connections with other cables
Click to expand...

there is your problem, your not splitting your 2nd pair

white/orange, orange, white/green, blue, white/blue, green, white/brown, brown

it dose make a difference. do this on both ends.
 
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