joekasmijan
asked on
Question on NIC's speed and duplex
I have set up 3 Dell computers on a wired network through a Linksys DSL router. Two of them are about 50 feet away from the router and the third one is next to it. I have no problem with the third computer, goes on-line fine with 100 Mbps NIC speed. The other two computers, I was able to make them get IP addresses from the router after setting the NIC's speed and duplex to 10 Mbps full. When set at default (Auto) they gave unpredicted results. Typing IPCONFIG will give either 0.0.0.0 or IP addresses that didn't start with 192.168.1.x. When I set up one of these computers next to the router, then it works fine like the third computer. Do I have problem with weak signal? Could this problem be fixed by connecting them to a switch/hub from the router?
Any help is greatly appreciated.
Any help is greatly appreciated.
SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
ASKER
Thank you to all of you.
>is the short cable still fast when you plug it into one of the ports that the slow computers were using?
Yes, a short cable on any port works good on any computer connected to it. To clarify further, I even connected my laptop to the 50 feet cables, I experienced the same problem.
>Are the ends on your cables hand-crimped, or did you buy machine-crimped cables?
I hand-crimped them my self.
>what happens if the two computers are set to 100Mbps/Full manually ???
I remembered it right, it gave me the same result (not able to go on-line)
>exchange network NICs on near and far computers and observe the result
The NICs are buit-in to the motherboard in all of them, they are Broadcom 440x.
I'll give it a try with factory-crimped long cable next week and let all of you know the result.
Thanks again.
>is the short cable still fast when you plug it into one of the ports that the slow computers were using?
Yes, a short cable on any port works good on any computer connected to it. To clarify further, I even connected my laptop to the 50 feet cables, I experienced the same problem.
>Are the ends on your cables hand-crimped, or did you buy machine-crimped cables?
I hand-crimped them my self.
>what happens if the two computers are set to 100Mbps/Full manually ???
I remembered it right, it gave me the same result (not able to go on-line)
>exchange network NICs on near and far computers and observe the result
The NICs are buit-in to the motherboard in all of them, they are Broadcom 440x.
I'll give it a try with factory-crimped long cable next week and let all of you know the result.
Thanks again.
ASKER CERTIFIED SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
ASKER
Yo are right The--Captain and Cagri. I bought a 50 foot machine-crimped cable and it works like a champ. I have a feeling it depends on the NIC card also. I have been crimping long cables, over the ceiling and never had any problem until this Dell computer Broadcom 440x NIC. The reason why I said that, the guy that I do this work on, has another store in a different place that is having excatly the same problem (smae thpe of computers). Another tech installed the network couple years ago and he didn't even noticed the problem until I told him. I'll check if it is cable problem the next time I'm there. How should I split the points? 50-50?
>Another tech installed the network couple years ago and he didn't even noticed the problem until I told him
Yup. A cable will typically avoid being confirmed as out-of-spec until it is either tested with equipment that verifies it's electrical tolerances (a decent cable tester), or until it meets the wrong combination of equipment. The problem is, an out-of-spec cable will work with lots of equipment, since a powerful ethernet tranceiver may be able to compensate for electrical deficiences in the cable - unfortunately, some equipment relies on having a cable that is completely electrically compliant (why else even bother to have a standard), and such equipment will fail (or perform sub-optimally) when presented with a substandard cable.
When I worked at the ISP, we had several hand-crimp tools - some would almost always produce crappy cables, some were about 50-50, and some produced mostly good cables - the point is *all* of them produced bad cables at some point, and there was no telling which were good and which were bad (you could tell the obvious really bad crimps just by looking, but that was about it) without a decent cable tester, and even then some of the good ones would go bad with sufficient wiggling.
The only consistent success I have had with hand-crimping is with those self-crimping modular patch panel jacks (you know, the ones that pop out of the chassis via plastic clips, and you can pry them apart with a flathead screwdriver by pressing on the release tab underneath). Those seem to work since they have punch-block style connections that cut into and grab the wire in a perpendicular fashion (like a punch block) rather than relying on a single tiny copper blade to cut into and rest against the wire in a parallel fashion (as in a male RJ-45 end). I keep a couple of those patch panel jacks in my laptop bag in case I need to quickly fashion a crossover cable (ethernet, T1, ATM) on-site.
> I have a feeling it depends on the NIC card also
I have no doubt of that - some NICs have more powerful transceivers than others
Take Nancy Reagan's advice and just say no to hand-crimped cables - you'll be glad you did in the long run.
Cheers,
-Jon
P.S. If you want to split pts 50-50, let me know - as PE, I can do it for you.
Yup. A cable will typically avoid being confirmed as out-of-spec until it is either tested with equipment that verifies it's electrical tolerances (a decent cable tester), or until it meets the wrong combination of equipment. The problem is, an out-of-spec cable will work with lots of equipment, since a powerful ethernet tranceiver may be able to compensate for electrical deficiences in the cable - unfortunately, some equipment relies on having a cable that is completely electrically compliant (why else even bother to have a standard), and such equipment will fail (or perform sub-optimally) when presented with a substandard cable.
When I worked at the ISP, we had several hand-crimp tools - some would almost always produce crappy cables, some were about 50-50, and some produced mostly good cables - the point is *all* of them produced bad cables at some point, and there was no telling which were good and which were bad (you could tell the obvious really bad crimps just by looking, but that was about it) without a decent cable tester, and even then some of the good ones would go bad with sufficient wiggling.
The only consistent success I have had with hand-crimping is with those self-crimping modular patch panel jacks (you know, the ones that pop out of the chassis via plastic clips, and you can pry them apart with a flathead screwdriver by pressing on the release tab underneath). Those seem to work since they have punch-block style connections that cut into and grab the wire in a perpendicular fashion (like a punch block) rather than relying on a single tiny copper blade to cut into and rest against the wire in a parallel fashion (as in a male RJ-45 end). I keep a couple of those patch panel jacks in my laptop bag in case I need to quickly fashion a crossover cable (ethernet, T1, ATM) on-site.
> I have a feeling it depends on the NIC card also
I have no doubt of that - some NICs have more powerful transceivers than others
Take Nancy Reagan's advice and just say no to hand-crimped cables - you'll be glad you did in the long run.
Cheers,
-Jon
P.S. If you want to split pts 50-50, let me know - as PE, I can do it for you.
ASKER
Thanks for all the info and advise regarding this matter. Now I know and learned something new. Yes, let split 50-50 and make everybody happy!
No problem - I gave myself the 1 extra point (since it couldn't be split exactly 50-50) for doing the legwork.
Cheers,
-Jon
Cheers,
-Jon
Sounds likely.
>Could this problem be fixed by connecting them to a switch/hub from the router?
I doubt it - is the short cable still fast when you plug it into one of the ports that the slow computers were using?
Are the ends on your cables hand-crimped, or did you buy machine-crimped cables?
Cheers,
-Jon