Crossover cables - is there a maximum length?

[amart]

I am connecting 2 win2k pc's using a direct connection crossover
cable.

It all works fine with my short 2 metre cable, but I cannot get it
working with a long 30 metre cable (I have tested the long cable with
a multimeter and it looks fine).

When I plug it in it takes about 20 seconds for the network cards
small led light to turn on, then the connection shows up on the tool
bar saying it is 100Mbits. Both pc's try to talk, ie. they send
packets, but no response, neither one receives packets.

Is this because the cable is too long? Do i need a straight cable
through a hub to be able to go over this distance, or could it be
something else?

Many thanks.

 

[Pegasus \(MVP\)]

I am connecting 2 win2k pc's using a direct connection crossover
cable.

It all works fine with my short 2 metre cable, but I cannot get it
working with a long 30 metre cable (I have tested the long cable with
a multimeter and it looks fine).

When I plug it in it takes about 20 seconds for the network cards
small led light to turn on, then the connection shows up on the tool
bar saying it is 100Mbits. Both pc's try to talk, ie. they send
packets, but no response, neither one receives packets.

Is this because the cable is too long? Do i need a straight cable
through a hub to be able to go over this distance, or could it be
something else?

Many thanks.

The cable may be incorrectly terminated, i.e. each
wire must be connected to the correct pin in the RJ45
connector.

 

[Jay Somerset]

I am connecting 2 win2k pc's using a direct connection crossover
cable.

It all works fine with my short 2 metre cable, but I cannot get it
working with a long 30 metre cable (I have tested the long cable with
a multimeter and it looks fine).

When I plug it in it takes about 20 seconds for the network cards
small led light to turn on, then the connection shows up on the tool
bar saying it is 100Mbits. Both pc's try to talk, ie. they send
packets, but no response, neither one receives packets.

Is this because the cable is too long? Do i need a straight cable
through a hub to be able to go over this distance, or could it be
something else?

Many thanks.

30 meters (100 ft) is pretty close to the maximum, especially if it is an
older (Cat 3 or 4) cable. Make sure that you are using Cat 5 cable, and
that it is correctly wired as a cross-over.

 

[Jetro]

Maximum distance between the Ethernet nodes using UTP cable either Cat3, 4,
or 5 is 100 meters (straight line). 1000BaseTX over Cat5 length is 25 meters
but yet 100 meters over Cat5e.
Ensure you got Cat5 rated jacks and cable. Aside of bad cable/jacks, it was
always the cheap/built-in NICs in my experience.

 

[Oli Restorick [MVP]]

I thought the limit was 100 meters for 100BaseT. I don't think it changes
because the cable is a cross-over.

Oli

 

[Steven L Umbach]

That's what I thought also and is shown in the link below. My house is less than 100
feet long though so I can not say for sure. --- Steve

http://www.bluemax.net/techtips/networking/Wiring_Tips/Wiring100TX/letsmakesomecables.htm

 

[Pegasus \(MVP\)]

It's 100 meters, not feet!

That's what I thought also and is shown in the link below. My house is less than 100
feet long though so I can not say for sure. --- Steve

http://www.bluemax.net/techtips/networking/Wiring_Tips/Wiring100TX/letsmakesomecables.htm

 

[Jay Somerset]

It's 100 meters, not feet!

Sorry -- I always seem to get metric/standard conversions inverted.

 

[Phillip Windell]

Sorry -- I always seem to get metric/standard conversions inverted.

The length of 100m is for a perfectly terminated cable under perfect
conditions. A poorly terminated cable such as an incorrect wiring pattern
or just a "sloppy" job using a correct pattern can reduce the usable length.
Also outside interference (fluorescent lights, power cables and lines) can
also limited the distance.

 

[Steven L Umbach]

Rats can be a problem also. --- Steve

 

[Phillip Windell]

Ha! Hadn't thought of that. I have had mice ge into some things here. I
have some of those ketchup, mustard, etc., packets left over from lunch
sometimes,..they've chrewed those open and the stuff ran all over the
shelves at times,....which,..hmm....could draw Bugs?


--

Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com

Rats can be a problem also. --- Steve