Hi All,

Had a weird on e yesterday.

I installed a computer at a new location for a customer.
The network cable from the wall worked fine
directly into the computer. But then I plugged it
into a little 5 port hub. Then no worky. A
different brand hub later and still no worky.
Hmmmm.

Well the master hub the wall cable was plugged into was
across the room, so I strung a 25' cable from the
little hub to the master hub. Worked!

Moral of the story. Please do not use electricians
to string data cable(s). They always screw something up.

-T

T wrote:
> Hi All,
>
> Had a weird on e yesterday.
>
> I installed a computer at a new location for a customer.
> The network cable from the wall worked fine
> directly into the computer.  But then I plugged it
> into a little 5 port hub.  Then no worky.  A
> different brand hub later and still no worky.
> Hmmmm.
>
> Well the master hub the wall cable was plugged into was
> across the room, so I strung a 25' cable from the
> little hub to the master hub.  Worked!
>
> Moral of the story.  Please do not use electricians
> to string data cable(s).  They always screw something up.
>

Who wires keystone jacks without testing them afterwards? You don't own
a tester either?

--
Take care,

Jonathan
-------------------
LITTLE WORKS STUDIO
http://www.LittleWorksStudio.com

T wrote:

> I installed a computer at a new location for a customer.
> The network cable from the wall worked fine
> directly into the computer. But then I plugged it
> into a little 5 port hub. Then no worky. A
> different brand hub later and still no worky.
> Hmmmm.
>
> Well the master hub the wall cable was plugged into was
> across the room, so I strung a 25' cable from the
> little hub to the master hub. Worked!
>
> Moral of the story. Please do not use electricians
> to string data cable(s). They always screw something up.

Doesn't look like the electricians that wired the RJ-45 wall jacks made
a mistake, especially since you said the wall jacks work. It was the
Ethernet hubs that didn't work. Computer wired to wall jack: works.
Computer to hub to wall jack: doesn't work. Hmm, sure looks like the
hubs were at fault. If you meant the wall jack nearest the computer
didn't work, still might not be the fault of whoever wired up the wall
jack. In most corporate setups, the wall jacks go to a patch panel.
Could be that RJ45 wall jack never got connected to the patch panel, or
the other side of the paired contacts didn't get wired to the network
source. Since the patch panel works by sliding the solid wire into a
slot between contacts that slice through the insulation, a poor patch
panel job could be at fault, or the wiring was strained to break the
connection from wire to patch panel prong. I've used splices that were
basically the same (e.g., 3M Scotchlok): a piece of metal with slots
into which wires were pushed to slice away their insulation to pinch
against the wires.

https://www.waytekwire.com/images/items/18-14GA_3M_IDC_Tap_Connector_31562_f.png

I don't like those except out of weather (i.e., indoors) and when the
only choice or for temporary use, because they cannot handle the full
amperage load for the wire (they're only touching 2 sides of the wire),
and they're susceptible to the wire walking out of the pinch, or the
wire or prong getting oxidized and corroding the connection (and
electrolysis can cause the oxidation since the prongs are often
iron-based but the wire is copper). Different metals expand at
different rates which can also effect the wire walking out of the
splice, and why you should never splice together aluminum and copper
wiring in your house unless using specialized splices (e.g.,
https://www.google.com/search?client=firefox-b-1-d&q=COPALUM which is
pricey, or AlumiConn splices). I've seen where homeowners have soldered
aluminum and copper wires together, and a splice is just an insulating
cover, but I suspect solder is not really that strong a bond; you're not
welding the wires together. Pinched connections, like Scotchlok or the
Ethernet patch panel, are okay for low-load use, and the connection does
not get disturbed.

Did you plug the walwart into the Ethernet hub, so it had power? You
plugged the computer into the hub, but did you plug the hub into the
wall jack?

Why use an Ethernet hub instead of a switch? Last time I checked,
getting a router (don't they all have switches now?) was about the same
price as getting an Ethernet switch. A hub would share bandwith across
multiple devices versus a switch where the device gets full bandwidth
(during its active cycle). You can get a 5-port Ethernet unmanaged
switch for under $12
(https://www.newegg.com/trendnet-te100-s5-5-x-rj45/p/N82E16833156066).

A hub with just one input jack and just one output jack isn't much of a
hub, and the same for a switch, or a router with a switch. It wouldn't
need more than to string a passive cable from jack to jack, so you might
as well as use a long Ethernet cable, or shorter ones with a
double-female RJ-45 connector (aka coupler), like:

https://www.newegg.com/p/2WG-01Y3-00005?Item=9SIAP81FWJ1316

For a multi-port Ethernet hub/switch, it needs power. Although it might
seem demeaning to ask, shit happens, so did you plug the A/C adapter
into the hub/switch, and check there was power at the wall outlet, power
strip, or wherever you into which plugged the A/C adapter? I've seen
where users plugged into a switched outlet, but the wall switch was in
the Off position, or into a power/surge strip, but the Power switch was
off, or its circuit breaker had snapped and need to be reset.

If all you wanted was to hook the RJ45 port in the computer to an RJ45
wall jack, why would you insert an Ethernet hub/switch into the line?
That would be if you intended to connect other Ethernet devices to the
same hub/switch as the computer, or you were planning for future
expansion capability. I've seen them used when the cable wasn't long
enough, and a hub/switch used to append another cable to extend the
reach, but you're adding more links in the chain to add complexity
versus just getting a longer cable. You can have Ethernet cabling up to
100 meters before requiring conditioning (repeater, switch) to pass
further the signal. That's a huge room for a 100 meter (328 ft) cable
to not reach from wall jack to computer.

If you're doing computer work for customers, you really should have an
RJ-45 crimper, a pack of RJ-45 crimp-on jacks, and a spool of cable to
make your own Ethernet cable to the required length instead of buying
pre-made cables that are way too long having to leave a coil of the
remainder tucked under somewhere to hide it. I have those. Lets me
make a shorty cable that runs from cable modem to network device sitting
right next to the cable modem without having to order a shorty and wait
for it to show up. Let me configure the cables to the right length when
wiring the RJ-45 wall jacks in my home instead of tucking a coil of
extra cable into the wall. I leave extra cable tucked in the wall for
later rework, but not 20 feet of it.

On 3/24/22 16:52, Jonathan N. Little wrote:
> T wrote:
>> Hi All,
>>
>> Had a weird on e yesterday.
>>
>> I installed a computer at a new location for a customer.
>> The network cable from the wall worked fine
>> directly into the computer.  But then I plugged it
>> into a little 5 port hub.  Then no worky.  A
>> different brand hub later and still no worky.
>> Hmmmm.
>>
>> Well the master hub the wall cable was plugged into was
>> across the room, so I strung a 25' cable from the
>> little hub to the master hub.  Worked!
>>
>> Moral of the story.  Please do not use electricians
>> to string data cable(s).  They always screw something up.
>>
>
>
> Who wires keystone jacks without testing them afterwards?
Electricians
> You don't own a tester either?
Don't need one. The low voltage guys I recommend
all have thousand dollar units and their stuff in
impeccable when they finish. I have had them
go in after electricians to fix things and they
just shake their heads in amazement.

On 3/24/22 16:57, VanguardLH wrote:
> T wrote:
>
>> I installed a computer at a new location for a customer.
>> The network cable from the wall worked fine
>> directly into the computer. But then I plugged it
>> into a little 5 port hub. Then no worky. A
>> different brand hub later and still no worky.
>> Hmmmm.
>>
>> Well the master hub the wall cable was plugged into was
>> across the room, so I strung a 25' cable from the
>> little hub to the master hub. Worked!
>>
>> Moral of the story. Please do not use electricians
>> to string data cable(s). They always screw something up.
>
> Doesn't look like the electricians that wired the RJ-45 wall jacks made
> a mistake, especially since you said the wall jacks work. It was the
> Ethernet hubs that didn't work. Computer wired to wall jack: works.
> Computer to hub to wall jack: doesn't work. Hmm, sure looks like the
> hubs were at fault. If you meant the wall jack nearest the computer
> didn't work, still might not be the fault of whoever wired up the wall
> jack. In most corporate setups, the wall jacks go to a patch panel.
> Could be that RJ45 wall jack never got connected to the patch panel, or
> the other side of the paired contacts didn't get wired to the network
> source. Since the patch panel works by sliding the solid wire into a
> slot between contacts that slice through the insulation, a poor patch
> panel job could be at fault, or the wiring was strained to break the
> connection from wire to patch panel prong. I've used splices that were
> basically the same (e.g., 3M Scotchlok): a piece of metal with slots
> into which wires were pushed to slice away their insulation to pinch
> against the wires.
>
> https://www.waytekwire.com/images/items/18-14GA_3M_IDC_Tap_Connector_31562_f.png
>
> I don't like those except out of weather (i.e., indoors) and when the
> only choice or for temporary use, because they cannot handle the full
> amperage load for the wire (they're only touching 2 sides of the wire),
> and they're susceptible to the wire walking out of the pinch, or the
> wire or prong getting oxidized and corroding the connection (and
> electrolysis can cause the oxidation since the prongs are often
> iron-based but the wire is copper). Different metals expand at
> different rates which can also effect the wire walking out of the
> splice, and why you should never splice together aluminum and copper
> wiring in your house unless using specialized splices (e.g.,
> https://www.google.com/search?client=firefox-b-1-d&q=COPALUM which is
> pricey, or AlumiConn splices). I've seen where homeowners have soldered
> aluminum and copper wires together, and a splice is just an insulating
> cover, but I suspect solder is not really that strong a bond; you're not
> welding the wires together. Pinched connections, like Scotchlok or the
> Ethernet patch panel, are okay for low-load use, and the connection does
> not get disturbed.
>
> Did you plug the walwart into the Ethernet hub, so it had power? You
> plugged the computer into the hub, but did you plug the hub into the
> wall jack?
>
> Why use an Ethernet hub instead of a switch?

Both tested hubs were switching hubs. A lot of folks
do not realize the old style and the new style are
both hubs:

https://en.wikipedia.org/wiki/Network_switch

A network switch (also called switching hub,
bridging hub, and, by the IEEE, MAC bridge)
is networking hardware that connects devices
on a computer network by using packet switching
to receive and forward data to the destination
device.

I use the term "hub" becasue it is correct English and
it is less confusing to my customers. A switch is what
the flick to turn their lights on. And everyone
understand the term "hub". No one knows
what a "MAC bridge" is.

I do carry an old style USB powered 10 base-T hub
for use with Wire Shark. Switching Hubs good
Wire Shark up big time

> Last time I checked,
> getting a router (don't they all have switches now?) was about the same
> price as getting an Ethernet switch. A hub would share bandwith across
> multiple devices versus a switch where the device gets full bandwidth
> (during its active cycle). You can get a 5-port Ethernet unmanaged
> switch for under $12
> (https://www.newegg.com/trendnet-te100-s5-5-x-rj45/p/N82E16833156066).
>
> A hub with just one input jack and just one output jack isn't much of a
> hub, and the same for a switch, or a router with a switch. It wouldn't
> need more than to string a passive cable from jack to jack, so you might
> as well as use a long Ethernet cable, or shorter ones with a
> double-female RJ-45 connector (aka coupler), like:

I still see some Charter/Spectrum cable modems/routers
with a single LAN output. They require a hub for
sharing between more devices

>
> https://www.newegg.com/p/2WG-01Y3-00005?Item=9SIAP81FWJ1316
>
> For a multi-port Ethernet hub/switch, it needs power. Although it might
> seem demeaning to ask, shit happens, so did you plug the A/C adapter
> into the hub/switch, and check there was power at the wall outlet, power
> strip, or wherever you into which plugged the A/C adapter? I've seen
> where users plugged into a switched outlet, but the wall switch was in
> the Off position, or into a power/surge strip, but the Power switch was
> off, or its circuit breaker had snapped and need to be reset.
>
> If all you wanted was to hook the RJ45 port in the computer to an RJ45
> wall jack, why would you insert an Ethernet hub/switch into the line?
> That would be if you intended to connect other Ethernet devices to the
> same hub/switch as the computer, or you were planning for future
> expansion capability. I've seen them used when the cable wasn't long
> enough, and a hub/switch used to append another cable to extend the
> reach, but you're adding more links in the chain to add complexity
> versus just getting a longer cable. You can have Ethernet cabling up to
> 100 meters before requiring conditioning (repeater, switch) to pass
> further the signal. That's a huge room for a 100 meter (328 ft) cable
> to not reach from wall jack to computer.
>
> If you're doing computer work for customers, you really should have an
> RJ-45 crimper, a pack of RJ-45 crimp-on jacks, and a spool of cable to
> make your own Ethernet cable to the required length instead of buying
> pre-made cables that are way too long having to leave a coil of the
> remainder tucked under somewhere to hide it. I have those. Lets me
> make a shorty cable that runs from cable modem to network device sitting
> right next to the cable modem without having to order a shorty and wait
> for it to show up. Let me configure the cables to the right length when
> wiring the RJ-45 wall jacks in my home instead of tucking a coil of
> extra cable into the wall. I leave extra cable tucked in the wall for
> later rework, but not 20 feet of it.

I have guys that do that for me. And they all have those
fancy $1000 testers. Their work is impeccable. I hav
a crimpers somewhere. Never used it in 28 years.

Straight hub to hub worked.

And two different hubs from different vendors had
the same issue. It was not the hubs or straight
hub to hub would not have worked.

On 2022-03-24 7:45 p.m., T wrote:
> On 3/24/22 16:52, Jonathan N. Little wrote:
>> T wrote:
>>> Hi All,
>>>
>>> Had a weird on e yesterday.
>>>
>>> I installed a computer at a new location for a customer.
>>> The network cable from the wall worked fine
>>> directly into the computer.  But then I plugged it
>>> into a little 5 port hub.  Then no worky.  A
>>> different brand hub later and still no worky.
>>> Hmmmm.
>>>
>>> Well the master hub the wall cable was plugged into was
>>> across the room, so I strung a 25' cable from the
>>> little hub to the master hub.  Worked!
>>>
>>> Moral of the story.  Please do not use electricians
>>> to string data cable(s).  They always screw something up.
>>>
>>
>>
>> Who wires keystone jacks without testing them afterwards?
>
> Electricians
>
>> You don't own a tester either?
>
> Don't need one.  The low voltage guys I recommend
> all have thousand dollar units and their stuff in
> impeccable when they finish.    I have had them
> go in after electricians to fix things and they
> just shake their heads in amazement.
>

There are Electricians, and there are wannabe electricians, at my last
place of employment (15 years) As a licensed Power engineer, I also
held An electricians license to 600 volts.

As part of my duties I was in charge (hands on) of pulling in Cat5
cables through the raceways to some 90 PCs throughout the complex, some
pulls as long as 280 feet, Then terminating both ends with rj45
connectors, one at each computer and the other at the jack-field' in the
2 wiring closets.

My professional crimping tool cost about $100.00 cdn, non of your DIY
tools for me and I used only high quality connectors. I did all my own
crimping and testing, as this was a critical network, in all that time
we used about 4500 feet of Cat5 cable and I never had one failure
during my time there.

Rene

T wrote:
> On 3/24/22 16:52, Jonathan N. Little wrote:
>> T wrote:
>>> Hi All,
>>>
>>> Had a weird on e yesterday.
>>>
>>> I installed a computer at a new location for a customer.
>>> The network cable from the wall worked fine
>>> directly into the computer.  But then I plugged it
>>> into a little 5 port hub.  Then no worky.  A
>>> different brand hub later and still no worky.
>>> Hmmmm.
>>>
>>> Well the master hub the wall cable was plugged into was
>>> across the room, so I strung a 25' cable from the
>>> little hub to the master hub.  Worked!
>>>
>>> Moral of the story.  Please do not use electricians
>>> to string data cable(s).  They always screw something up.
>>>
>>
>>
>> Who wires keystone jacks without testing them afterwards?
>
> Electricians
>
>> You don't own a tester either?
>
> Don't need one.  The low voltage guys I recommend
> all have thousand dollar units and their stuff in
> impeccable when they finish.    I have had them
> go in after electricians to fix things and they
> just shake their heads in amazement.
>

Basic diag tool. One wire with a marginal connection can result in
intermittent network errors that you can chase your own tail if don't
test the connection first.

--
Take care,

Jonathan
-------------------
LITTLE WORKS STUDIO
http://www.LittleWorksStudio.com

On 3/24/22 18:14, Rene Lamontagne wrote:
> On 2022-03-24 7:45 p.m., T wrote:
>> On 3/24/22 16:52, Jonathan N. Little wrote:
>>> T wrote:
>>>> Hi All,
>>>>
>>>> Had a weird on e yesterday.
>>>>
>>>> I installed a computer at a new location for a customer.
>>>> The network cable from the wall worked fine
>>>> directly into the computer.  But then I plugged it
>>>> into a little 5 port hub.  Then no worky.  A
>>>> different brand hub later and still no worky.
>>>> Hmmmm.
>>>>
>>>> Well the master hub the wall cable was plugged into was
>>>> across the room, so I strung a 25' cable from the
>>>> little hub to the master hub.  Worked!
>>>>
>>>> Moral of the story.  Please do not use electricians
>>>> to string data cable(s).  They always screw something up.
>>>>
>>>
>>>
>>> Who wires keystone jacks without testing them afterwards?
>>
>> Electricians
>>
>>> You don't own a tester either?
>>
>> Don't need one.  The low voltage guys I recommend
>> all have thousand dollar units and their stuff in
>> impeccable when they finish.    I have had them
>> go in after electricians to fix things and they
>> just shake their heads in amazement.
>>
>
> There are Electricians, and there are wannabe electricians, at my last
> place of employment (15 years)   As a licensed  Power engineer, I also
> held An electricians license to 600 volts.
>
> As part of my duties I was in charge (hands on) of pulling in Cat5
> cables through the raceways to some 90 PCs throughout the complex, some
> pulls as long as 280 feet, Then terminating both ends with rj45
> connectors, one at each computer and the other at the jack-field' in the
> 2 wiring closets.
>
> My professional crimping tool cost about $100.00  cdn, non of your DIY
> tools for me and I used only high quality connectors. I did all my own
> crimping and testing, as this was a critical network, in all that time
> we used about 4500 feet of  Cat5 cable and I never had one failure
> during my time there.
>
> Rene
>
>
Hi Rene,
I have a bachelors degree in Electrical, Electronic, and
Computer engineering. I do not try to be an electrician.
And I have professionals that are absolute artists do
my cable stringing. Again, I know better. A man's
got to know his limitations.
I'd love to use you for cable stringing.
This problem I encountered was probably do to the
computer network card being more tolerant of
crappy cabling/connections then both hubs. Gave
me a run for my money, but I figured it out.
About 25 years ago, I got called into an electrical
firm to find out why their network was trash. They
stuck their server in a small closed closet. The
heat nearly singed my eyebrows when I opened the door.
I told them they had to take the door off and duct
an air conditioning vent into the room. I could
tell they were getting agitated with me.
Next step was to remove a wall plate to check the
wiring. No fooling, they splayed the cat 5 TEN
inches back. I told them they had to bring in a
professional to fix all their wiring. They
then had had it with me, told me they did the
wiring, and showed me the door. Idiots.
The current guys I use certify each drop with
a live data tester. They are awesome.
-T

On 3/24/22 20:26, Jonathan N. Little wrote:
> T wrote:
>> On 3/24/22 16:52, Jonathan N. Little wrote:
>>> T wrote:
>>>> Hi All,
>>>>
>>>> Had a weird on e yesterday.
>>>>
>>>> I installed a computer at a new location for a customer.
>>>> The network cable from the wall worked fine
>>>> directly into the computer.  But then I plugged it
>>>> into a little 5 port hub.  Then no worky.  A
>>>> different brand hub later and still no worky.
>>>> Hmmmm.
>>>>
>>>> Well the master hub the wall cable was plugged into was
>>>> across the room, so I strung a 25' cable from the
>>>> little hub to the master hub.  Worked!
>>>>
>>>> Moral of the story.  Please do not use electricians
>>>> to string data cable(s).  They always screw something up.
>>>>
>>>
>>>
>>> Who wires keystone jacks without testing them afterwards?
>>
>> Electricians
>>
>>> You don't own a tester either?
>>
>> Don't need one.  The low voltage guys I recommend
>> all have thousand dollar units and their stuff in
>> impeccable when they finish.    I have had them
>> go in after electricians to fix things and they
>> just shake their heads in amazement.
>>
>
> Basic diag tool. One wire with a marginal connection can result in
> intermittent network errors that you can chase your own tail if don't
> test the connection first.
Hi Jonathan,
Chasing your tail is a good description. I did
more than a few "what the hell's?"
One of the weird things was one of the Ethernet
connections from the little hub to a Brother printer
was dead too. Another "what the hell?". So I reset
the network configuration from the printers
config panel and happy camping returned.
One of the funnest parts of my job is networking
printers.
Also, after install the HP laser printer, it
did not show up in Devices and Printers, but
each printing showed it. I've seen that before.
So I installed the Brother printer. Soon as
the Brother printer showed up in Devices and
Printers, so did the HP. Windows 10 strikes again.
-T

T wrote:
> Hi All,
>
> Had a weird on e yesterday.
>
> I installed a computer at a new location for a customer.
> The network cable from the wall worked fine
> directly into the computer.  But then I plugged it
> into a little 5 port hub.  Then no worky.  A
> different brand hub later and still no worky.
> Hmmmm.
>
> Well the master hub the wall cable was plugged into was
> across the room, so I strung a 25' cable from the
> little hub to the master hub.  Worked!
>
> Moral of the story.  Please do not use electricians
> to string data cable(s).  They always screw something up.
>
> -T

:) When did the electricians install the wiring to the wall cable outlet?

--
....w¡ñ§±¤ñ

On 2022-03-25 12:51 a.m., T wrote:
> On 3/24/22 18:14, Rene Lamontagne wrote:
>> On 2022-03-24 7:45 p.m., T wrote:
>>> On 3/24/22 16:52, Jonathan N. Little wrote:
>>>> T wrote:
>>>>> Hi All,
>>>>>
>>>>> Had a weird on e yesterday.
>>>>>
>>>>> I installed a computer at a new location for a customer.
>>>>> The network cable from the wall worked fine
>>>>> directly into the computer.  But then I plugged it
>>>>> into a little 5 port hub.  Then no worky.  A
>>>>> different brand hub later and still no worky.
>>>>> Hmmmm.
>>>>>
>>>>> Well the master hub the wall cable was plugged into was
>>>>> across the room, so I strung a 25' cable from the
>>>>> little hub to the master hub.  Worked!
>>>>>
>>>>> Moral of the story.  Please do not use electricians
>>>>> to string data cable(s).  They always screw something up.
>>>>>
>>>>
>>>>
>>>> Who wires keystone jacks without testing them afterwards?
>>>
>>> Electricians
>>>
>>>> You don't own a tester either?
>>>
>>> Don't need one.  The low voltage guys I recommend
>>> all have thousand dollar units and their stuff in
>>> impeccable when they finish.    I have had them
>>> go in after electricians to fix things and they
>>> just shake their heads in amazement.
>>>
>>
>> There are Electricians, and there are wannabe electricians, at my last
>> place of employment (15 years)   As a licensed  Power engineer, I also
>> held An electricians license to 600 volts.
>>
>> As part of my duties I was in charge (hands on) of pulling in Cat5
>> cables through the raceways to some 90 PCs throughout the complex,
>> some pulls as long as 280 feet, Then terminating both ends with rj45
>> connectors, one at each computer and the other at the jack-field' in
>> the 2 wiring closets.
>>
>> My professional crimping tool cost about $100.00  cdn, non of your DIY
>> tools for me and I used only high quality connectors. I did all my own
>> crimping and testing, as this was a critical network, in all that time
>> we used about 4500 feet of  Cat5 cable and I never had one failure
>> during my time there.
>>
>> Rene
>>
>>
>
> Hi Rene,
>
> I have a bachelors degree in Electrical, Electronic, and
> Computer engineering.  I do not try to be an electrician.
> And I have professionals that are absolute artists do
> my cable stringing.  Again, I know better.  A man's
> got to know his limitations.
>
> I'd love to use you for cable stringing.
> This problem I encountered was probably do to the
> computer network card being more tolerant of
> crappy cabling/connections then both hubs.  Gave
> me a run for my money, but I figured it out.
>
> About 25 years ago, I got called into an electrical
> firm to find out why their network was trash.  They
> stuck their server in a small closed closet.  The
> heat nearly singed my eyebrows when I opened the door.
>
> I told them they had to take the door off and duct
> an air conditioning vent into the room.  I could
> tell they were getting agitated with me.
>
> Next step was to remove a wall plate to check the
> wiring.  No fooling, they splayed the cat 5 TEN
> inches back.  I told them they had to bring in a
> professional to fix all their wiring.  They
> then had had it with me, told me they did the
> wiring, and showed me the door.  Idiots.
>
> The current guys I use certify each drop with
> a live data tester.  They are awesome.
>
> -T

Thanks, I took great pride in my work, Good show, when you want good
work hire a good Professional team. a few extra dollars buys you no
callbacks and problems.

Rene

On 3/25/2022 9:49 AM, Rene Lamontagne wrote:
> On 2022-03-25 12:51 a.m., T wrote:
>> On 3/24/22 18:14, Rene Lamontagne wrote:
>>> On 2022-03-24 7:45 p.m., T wrote:
>>>> On 3/24/22 16:52, Jonathan N. Little wrote:
>>>>> T wrote:
>>>>>> Hi All,
>>>>>>
>>>>>> Had a weird on e yesterday.
>>>>>>
>>>>>> I installed a computer at a new location for a customer.
>>>>>> The network cable from the wall worked fine
>>>>>> directly into the computer.  But then I plugged it
>>>>>> into a little 5 port hub.  Then no worky.  A
>>>>>> different brand hub later and still no worky.
>>>>>> Hmmmm.
>>>>>>
>>>>>> Well the master hub the wall cable was plugged into was
>>>>>> across the room, so I strung a 25' cable from the
>>>>>> little hub to the master hub.  Worked!
>>>>>>
>>>>>> Moral of the story.  Please do not use electricians
>>>>>> to string data cable(s).  They always screw something up.
>>>>>>
>>>>>
>>>>>
>>>>> Who wires keystone jacks without testing them afterwards?
>>>>
>>>> Electricians
>>>>
>>>>> You don't own a tester either?
>>>>
>>>> Don't need one.  The low voltage guys I recommend
>>>> all have thousand dollar units and their stuff in
>>>> impeccable when they finish.    I have had them
>>>> go in after electricians to fix things and they
>>>> just shake their heads in amazement.
>>>>
>>>
>>> There are Electricians, and there are wannabe electricians, at my last place of employment (15 years)   As a licensed  Power engineer, I also held An electricians license to 600 volts.
>>>
>>> As part of my duties I was in charge (hands on) of pulling in Cat5 cables through the raceways to some 90 PCs throughout the complex, some pulls as long as 280 feet, Then terminating both ends with rj45 connectors, one at each computer and the other at the jack-field' in the 2 wiring closets.
>>>
>>> My professional crimping tool cost about $100.00  cdn, non of your DIY tools for me and I used only high quality connectors. I did all my own crimping and testing, as this was a critical network, in all that time we used about 4500 feet of  Cat5 cable and I never had one failure during my time there.
>>>
>>> Rene
>>>
>>>
>>
>> Hi Rene,
>>
>> I have a bachelors degree in Electrical, Electronic, and
>> Computer engineering.  I do not try to be an electrician.
>> And I have professionals that are absolute artists do
>> my cable stringing.  Again, I know better.  A man's
>> got to know his limitations.
>>
>> I'd love to use you for cable stringing.
>> This problem I encountered was probably do to the
>> computer network card being more tolerant of
>> crappy cabling/connections then both hubs.  Gave
>> me a run for my money, but I figured it out.
>>
>> About 25 years ago, I got called into an electrical
>> firm to find out why their network was trash.  They
>> stuck their server in a small closed closet.  The
>> heat nearly singed my eyebrows when I opened the door.
>>
>> I told them they had to take the door off and duct
>> an air conditioning vent into the room.  I could
>> tell they were getting agitated with me.
>>
>> Next step was to remove a wall plate to check the
>> wiring.  No fooling, they splayed the cat 5 TEN
>> inches back.  I told them they had to bring in a
>> professional to fix all their wiring.  They
>> then had had it with me, told me they did the
>> wiring, and showed me the door.  Idiots.
>>
>> The current guys I use certify each drop with
>> a live data tester.  They are awesome.
>>
>> -T
>
>  Thanks, I took great pride in my work, Good show, when you want good work hire a good Professional team. a few extra dollars buys you no callbacks and problems.
>
> Rene

Even if the TP were splayed (the outer insulation layer removed
allowing the wire pairs to spread out a little), that should not
affect operation. If someone tried to untwist a length of each
pair, that would be bad.

The details around a connector matter, in the sense that
the "connector impedance" can be a problem. That's where the
notion of "RF connectors" came in, in discussions at work.
"Is it an RF quality connector?" was meant to imply that
looking into it with a network analyzer out to some number
of GHz, it maintained a 50 ohm impedance, suited to matching
things driving and receiving, around it.

The TP would be 100 ohms or 110 ohms or so. The Transformer
on each end of the link, would have a characteristic impedance
to match that. The design of the connector, does not suggest
any attempt at controlled impedance. There's no ground shield
around it (Ethernet doesn't need that), and a ground plane was
always part of making "RF connectors". Look at an SMA for an
example of the quality that goes into 2.5GHz or 5GHz connectors.

The wires are twisted, as part of handling crosstalk, and having
the transformer at the end, nullify some of that. You can have
large common-mode signals induced into those pairs, and it
"all still works". I've taken oscilloscope pictures of 10V P-P
signals riding (common mode, not diff) on pairs, and the transformer
rejection takes care of it, like magic. The shocker for me,
was not the fact the transformer was performing miracles,
it was the voltage the oscilloscope was claiming was present.
And that's just AC hum on the wires, but a hum of significant "fake"
amplitude.

I would sooner believe the network had a mixture of DHCP and
static assignments, and perhaps a duplicate address was affecting
things.

If it's GbE, a certain amount of defectivity can be removed
by the PHY during negotiation. It could drop the interface
to 100BT, if a "lucky choice" is made for the wiring defect.
I don't think MDI/MDIX can fix everything. It's sorta like
PCI express, that can correct a number of faults, simply
by automatically turning off some of the lanes and using
the remaining lanes. A person might never know, that
lane 9 on the x16 video card slot, had been busted for the last
five years. There's no warning in software.

One of the reasons for debugging stuff like this networking
problem, is to build your catalog of experience.

The Marvell NIC on one of the motherboards here, has a TDR on it,
and it can tell you "open, short, matched" on each of the four
pairs. You turn off the power on your Switch, so the transformers
are quiescent, and the Marvell NIC on the PC sends pulses down the line,
to evaluate the wiring. But that motherboard died, and my
attempts over the years to buy a standalone PCIe card, failed
to work out. One box from the computer store, said Marvell
on the outside, but a RealTek was inside. so now I have
no TDR to use.

There is still a copy of the Virtual Cable Tester whitepaper
at the bottom of this page. It has a couple pictures of
waveforms. And the VCT can give an estimate of how many feet
away the defect is. I don't know if it was stated anywhere,
as to the measurement uncertainty (+/- nanoseconds or feet).

https://www.teklib.com/library/vct-marvell-virtual-cable-tester-technology-for-gigabit-networks-white-paper/

Paul

T wrote:
> On 3/24/22 20:26, Jonathan N. Little wrote:
>> T wrote:
>>> On 3/24/22 16:52, Jonathan N. Little wrote:
>>>> T wrote:
>>>>> Hi All,
>>>>>
>>>>> Had a weird on e yesterday.
>>>>>
>>>>> I installed a computer at a new location for a customer.
>>>>> The network cable from the wall worked fine
>>>>> directly into the computer.  But then I plugged it
>>>>> into a little 5 port hub.  Then no worky.  A
>>>>> different brand hub later and still no worky.
>>>>> Hmmmm.
>>>>>
>>>>> Well the master hub the wall cable was plugged into was
>>>>> across the room, so I strung a 25' cable from the
>>>>> little hub to the master hub.  Worked!
>>>>>
>>>>> Moral of the story.  Please do not use electricians
>>>>> to string data cable(s).  They always screw something up.
>>>>>
>>>>
>>>>
>>>> Who wires keystone jacks without testing them afterwards?
>>>
>>> Electricians
>>>
>>>> You don't own a tester either?
>>>
>>> Don't need one.  The low voltage guys I recommend
>>> all have thousand dollar units and their stuff in
>>> impeccable when they finish.    I have had them
>>> go in after electricians to fix things and they
>>> just shake their heads in amazement.
>>>
>>
>> Basic diag tool. One wire with a marginal connection can result in
>> intermittent network errors that you can chase your own tail if don't
>> test the connection first.
>
> Hi Jonathan,
>
> Chasing your tail is a good description.  I did
> more than a few "what the hell's?"
>
> One of the weird things was one of the Ethernet
> connections from the little hub to a Brother printer
> was dead too. Another "what the hell?".  So I reset
> the network configuration from the printers
> config panel and happy camping returned.
>
> One of the funnest parts of my job is networking
> printers.
>
> Also, after install the HP laser printer, it
> did not show up in Devices and Printers, but
> each printing showed it.  I've seen that before.
> So I installed the Brother printer.  Soon as
> the Brother printer showed up in Devices and
> Printers, so did the HP. Windows 10 strikes again.

Okay this relates to your "confusion" between hub and switch. Hub,
switch, router, are devices in increasing "intelligence" in routing. A
hub it the "dumbest" of all where any traffic it receives on the network
is simply broadcasted on all ports. It is why a hub can create a noisy
LAN, but can also be helpful in diagnostics because you can see all the
communication on the network. I have an old hub on the shelf just for
such applications. A switch is a hub with extra processing to register
MAC addresses of connected devices on a network so when requests are
made they are not broadcasted over all port but directed only to the
port with destination's recorded MAC address. More efficient and allows
FULL DUPLEX communication between devices. It is also why, your printer
issue may have been illustrative, a switch's MAC table can get corrupted
or obsolete which can cause issues. Noted with older, cheaper switches
where power blips or switching cables too much would cause nodes not to
work and required power cycling the switch to resolve. Of course lastly
the router with more "intelligence" to handle connection between devices
on different networks with NAT.

--
Take care,

Jonathan
-------------------
LITTLE WORKS STUDIO
http://www.LittleWorksStudio.com

T wrote:

> On 3/24/22 20:26, Jonathan N. Little wrote:
>> T wrote:
>>> On 3/24/22 16:52, Jonathan N. Little wrote:
>>>> T wrote:
>>>>> Hi All,
>>>>>
>>>>> Had a weird on e yesterday.
>>>>>
>>>>> I installed a computer at a new location for a customer.
>>>>> The network cable from the wall worked fine
>>>>> directly into the computer.  But then I plugged it
>>>>> into a little 5 port hub.  Then no worky.  A
>>>>> different brand hub later and still no worky.
>>>>> Hmmmm.
>>>>>
>>>>> Well the master hub the wall cable was plugged into was
>>>>> across the room, so I strung a 25' cable from the
>>>>> little hub to the master hub.  Worked!
>>>>>
>>>>> Moral of the story.  Please do not use electricians
>>>>> to string data cable(s).  They always screw something up.
>>>>>
>>>>
>>>>
>>>> Who wires keystone jacks without testing them afterwards?
>>>
>>> Electricians
>>>
>>>> You don't own a tester either?
>>>
>>> Don't need one.  The low voltage guys I recommend
>>> all have thousand dollar units and their stuff in
>>> impeccable when they finish.    I have had them
>>> go in after electricians to fix things and they
>>> just shake their heads in amazement.
>>>
>>
>> Basic diag tool. One wire with a marginal connection can result in
>> intermittent network errors that you can chase your own tail if don't
>> test the connection first.
>
> Hi Jonathan,
>
> Chasing your tail is a good description. I did
> more than a few "what the hell's?"
>
> One of the weird things was one of the Ethernet
> connections from the little hub to a Brother printer
> was dead too. Another "what the hell?". So I reset
> the network configuration from the printers
> config panel and happy camping returned.
>
> One of the funnest parts of my job is networking
> printers.
>
> Also, after install the HP laser printer, it
> did not show up in Devices and Printers, but
> each printing showed it. I've seen that before.
> So I installed the Brother printer. Soon as
> the Brother printer showed up in Devices and
> Printers, so did the HP. Windows 10 strikes again.
>
> -T

That's what happens when boobs are allowed to have admin privileges
(i.e., login with admin privs under their Windows accounts). You're
battling with the other admins who are boobs. They probably haven't
even bothered to read a Dummies book.

On 3/25/22 06:49, Rene Lamontagne wrote:
> On 2022-03-25 12:51 a.m., T wrote:
>> On 3/24/22 18:14, Rene Lamontagne wrote:
>>> On 2022-03-24 7:45 p.m., T wrote:
>>>> On 3/24/22 16:52, Jonathan N. Little wrote:
>>>>> T wrote:
>>>>>> Hi All,
>>>>>>
>>>>>> Had a weird on e yesterday.
>>>>>>
>>>>>> I installed a computer at a new location for a customer.
>>>>>> The network cable from the wall worked fine
>>>>>> directly into the computer.  But then I plugged it
>>>>>> into a little 5 port hub.  Then no worky.  A
>>>>>> different brand hub later and still no worky.
>>>>>> Hmmmm.
>>>>>>
>>>>>> Well the master hub the wall cable was plugged into was
>>>>>> across the room, so I strung a 25' cable from the
>>>>>> little hub to the master hub.  Worked!
>>>>>>
>>>>>> Moral of the story.  Please do not use electricians
>>>>>> to string data cable(s).  They always screw something up.
>>>>>>
>>>>>
>>>>>
>>>>> Who wires keystone jacks without testing them afterwards?
>>>>
>>>> Electricians
>>>>
>>>>> You don't own a tester either?
>>>>
>>>> Don't need one.  The low voltage guys I recommend
>>>> all have thousand dollar units and their stuff in
>>>> impeccable when they finish.    I have had them
>>>> go in after electricians to fix things and they
>>>> just shake their heads in amazement.
>>>>
>>>
>>> There are Electricians, and there are wannabe electricians, at my
>>> last place of employment (15 years)   As a licensed  Power engineer,
>>> I also held An electricians license to 600 volts.
>>>
>>> As part of my duties I was in charge (hands on) of pulling in Cat5
>>> cables through the raceways to some 90 PCs throughout the complex,
>>> some pulls as long as 280 feet, Then terminating both ends with rj45
>>> connectors, one at each computer and the other at the jack-field' in
>>> the 2 wiring closets.
>>>
>>> My professional crimping tool cost about $100.00  cdn, non of your
>>> DIY tools for me and I used only high quality connectors. I did all
>>> my own crimping and testing, as this was a critical network, in all
>>> that time we used about 4500 feet of  Cat5 cable and I never had one
>>> failure during my time there.
>>>
>>> Rene
>>>
>>>
>>
>> Hi Rene,
>>
>> I have a bachelors degree in Electrical, Electronic, and
>> Computer engineering.  I do not try to be an electrician.
>> And I have professionals that are absolute artists do
>> my cable stringing.  Again, I know better.  A man's
>> got to know his limitations.
>>
>> I'd love to use you for cable stringing.
>> This problem I encountered was probably do to the
>> computer network card being more tolerant of
>> crappy cabling/connections then both hubs.  Gave
>> me a run for my money, but I figured it out.
>>
>> About 25 years ago, I got called into an electrical
>> firm to find out why their network was trash.  They
>> stuck their server in a small closed closet.  The
>> heat nearly singed my eyebrows when I opened the door.
>>
>> I told them they had to take the door off and duct
>> an air conditioning vent into the room.  I could
>> tell they were getting agitated with me.
>>
>> Next step was to remove a wall plate to check the
>> wiring.  No fooling, they splayed the cat 5 TEN
>> inches back.  I told them they had to bring in a
>> professional to fix all their wiring.  They
>> then had had it with me, told me they did the
>> wiring, and showed me the door.  Idiots.
>>
>> The current guys I use certify each drop with
>> a live data tester.  They are awesome.
>>
>> -T
>
>  Thanks, I took great pride in my work, Good show, when you want good
> work hire a good Professional team. a few extra dollars buys you no
> callbacks and problems.
>
> Rene

Not using professionals is like stepping over dollars
to save dimes

On 3/25/22 07:36, Paul wrote:
> Even if the TP were splayed (the outer insulation layer removed
> allowing the wire pairs to spread out a little), that should not
> affect operation. If someone tried to untwist a length of each
> pair, that would be bad.
By splayed, I meant that the insulation was removed
and the wires untwisted. I was not even sure the
proper colors were crimps which means trey had to do it
at both ends. My "dim" memory was that they grouped
the solid and the white striped together, but that
may have been another customer.

On 3/25/22 09:58, VanguardLH wrote:
> T wrote:
>
>> On 3/24/22 20:26, Jonathan N. Little wrote:
>>> T wrote:
>>>> On 3/24/22 16:52, Jonathan N. Little wrote:
>>>>> T wrote:
>>>>>> Hi All,
>>>>>>
>>>>>> Had a weird on e yesterday.
>>>>>>
>>>>>> I installed a computer at a new location for a customer.
>>>>>> The network cable from the wall worked fine
>>>>>> directly into the computer.  But then I plugged it
>>>>>> into a little 5 port hub.  Then no worky.  A
>>>>>> different brand hub later and still no worky.
>>>>>> Hmmmm.
>>>>>>
>>>>>> Well the master hub the wall cable was plugged into was
>>>>>> across the room, so I strung a 25' cable from the
>>>>>> little hub to the master hub.  Worked!
>>>>>>
>>>>>> Moral of the story.  Please do not use electricians
>>>>>> to string data cable(s).  They always screw something up.
>>>>>>
>>>>>
>>>>>
>>>>> Who wires keystone jacks without testing them afterwards?
>>>>
>>>> Electricians
>>>>
>>>>> You don't own a tester either?
>>>>
>>>> Don't need one.  The low voltage guys I recommend
>>>> all have thousand dollar units and their stuff in
>>>> impeccable when they finish.    I have had them
>>>> go in after electricians to fix things and they
>>>> just shake their heads in amazement.
>>>>
>>>
>>> Basic diag tool. One wire with a marginal connection can result in
>>> intermittent network errors that you can chase your own tail if don't
>>> test the connection first.
>>
>> Hi Jonathan,
>>
>> Chasing your tail is a good description. I did
>> more than a few "what the hell's?"
>>
>> One of the weird things was one of the Ethernet
>> connections from the little hub to a Brother printer
>> was dead too. Another "what the hell?". So I reset
>> the network configuration from the printers
>> config panel and happy camping returned.
>>
>> One of the funnest parts of my job is networking
>> printers.
>>
>> Also, after install the HP laser printer, it
>> did not show up in Devices and Printers, but
>> each printing showed it. I've seen that before.
>> So I installed the Brother printer. Soon as
>> the Brother printer showed up in Devices and
>> Printers, so did the HP. Windows 10 strikes again.
>>
>> -T
>
> That's what happens when boobs are allowed to have admin privileges
> (i.e., login with admin privs under their Windows accounts). You're
> battling with the other admins who are boobs. They probably haven't
> even bothered to read a Dummies book.
:-)

On 3/25/22 07:36, Paul wrote:
> On 3/25/2022 9:49 AM, Rene Lamontagne wrote:
>> On 2022-03-25 12:51 a.m., T wrote:
>>> On 3/24/22 18:14, Rene Lamontagne wrote:
>>>> On 2022-03-24 7:45 p.m., T wrote:
>>>>> On 3/24/22 16:52, Jonathan N. Little wrote:
>>>>>> T wrote:
>>>>>>> Hi All,
>>>>>>>
>>>>>>> Had a weird on e yesterday.
>>>>>>>
>>>>>>> I installed a computer at a new location for a customer.
>>>>>>> The network cable from the wall worked fine
>>>>>>> directly into the computer.  But then I plugged it
>>>>>>> into a little 5 port hub.  Then no worky.  A
>>>>>>> different brand hub later and still no worky.
>>>>>>> Hmmmm.
>>>>>>>
>>>>>>> Well the master hub the wall cable was plugged into was
>>>>>>> across the room, so I strung a 25' cable from the
>>>>>>> little hub to the master hub.  Worked!
>>>>>>>
>>>>>>> Moral of the story.  Please do not use electricians
>>>>>>> to string data cable(s).  They always screw something up.
>>>>>>>
>>>>>>
>>>>>>
>>>>>> Who wires keystone jacks without testing them afterwards?
>>>>>
>>>>> Electricians
>>>>>
>>>>>> You don't own a tester either?
>>>>>
>>>>> Don't need one.  The low voltage guys I recommend
>>>>> all have thousand dollar units and their stuff in
>>>>> impeccable when they finish.    I have had them
>>>>> go in after electricians to fix things and they
>>>>> just shake their heads in amazement.
>>>>>
>>>>
>>>> There are Electricians, and there are wannabe electricians, at my
>>>> last place of employment (15 years)   As a licensed  Power engineer,
>>>> I also held An electricians license to 600 volts.
>>>>
>>>> As part of my duties I was in charge (hands on) of pulling in Cat5
>>>> cables through the raceways to some 90 PCs throughout the complex,
>>>> some pulls as long as 280 feet, Then terminating both ends with rj45
>>>> connectors, one at each computer and the other at the jack-field' in
>>>> the 2 wiring closets.
>>>>
>>>> My professional crimping tool cost about $100.00  cdn, non of your
>>>> DIY tools for me and I used only high quality connectors. I did all
>>>> my own crimping and testing, as this was a critical network, in all
>>>> that time we used about 4500 feet of  Cat5 cable and I never had one
>>>> failure during my time there.
>>>>
>>>> Rene
>>>>
>>>>
>>>
>>> Hi Rene,
>>>
>>> I have a bachelors degree in Electrical, Electronic, and
>>> Computer engineering.  I do not try to be an electrician.
>>> And I have professionals that are absolute artists do
>>> my cable stringing.  Again, I know better.  A man's
>>> got to know his limitations.
>>>
>>> I'd love to use you for cable stringing.
>>> This problem I encountered was probably do to the
>>> computer network card being more tolerant of
>>> crappy cabling/connections then both hubs.  Gave
>>> me a run for my money, but I figured it out.
>>>
>>> About 25 years ago, I got called into an electrical
>>> firm to find out why their network was trash.  They
>>> stuck their server in a small closed closet.  The
>>> heat nearly singed my eyebrows when I opened the door.
>>>
>>> I told them they had to take the door off and duct
>>> an air conditioning vent into the room.  I could
>>> tell they were getting agitated with me.
>>>
>>> Next step was to remove a wall plate to check the
>>> wiring.  No fooling, they splayed the cat 5 TEN
>>> inches back.  I told them they had to bring in a
>>> professional to fix all their wiring.  They
>>> then had had it with me, told me they did the
>>> wiring, and showed me the door.  Idiots.
>>>
>>> The current guys I use certify each drop with
>>> a live data tester.  They are awesome.
>>>
>>> -T
>>
>>   Thanks, I took great pride in my work, Good show, when you want good
>> work hire a good Professional team. a few extra dollars buys you no
>> callbacks and problems.
>>
>> Rene
>
> Even if the TP were splayed (the outer insulation layer removed
> allowing the wire pairs to spread out a little), that should not
> affect operation. If someone tried to untwist a length of each
> pair, that would be bad.
>
> The details around a connector matter, in the sense that
> the "connector impedance" can be a problem. That's where the
> notion of "RF connectors" came in, in discussions at work.
> "Is it an RF quality connector?" was meant to imply that
> looking into it with a network analyzer out to some number
> of GHz, it maintained a 50 ohm impedance, suited to matching
> things driving and receiving, around it.
>
> The TP would be 100 ohms or 110 ohms or so. The Transformer
> on each end of the link, would have a characteristic impedance
> to match that. The design of the connector, does not suggest
> any attempt at controlled impedance. There's no ground shield
> around it (Ethernet doesn't need that), and a ground plane was
> always part of making "RF connectors". Look at an SMA for an
> example of the quality that goes into 2.5GHz or 5GHz connectors.
>
> The wires are twisted, as part of handling crosstalk, and having
> the transformer at the end, nullify some of that. You can have
> large common-mode signals induced into those pairs, and it
> "all still works". I've taken oscilloscope pictures of 10V P-P
> signals riding (common mode, not diff) on pairs, and the transformer
> rejection takes care of it, like magic. The shocker for me,
> was not the fact the transformer was performing miracles,
> it was the voltage the oscilloscope was claiming was present.
> And that's just AC hum on the wires, but a hum of significant "fake"
> amplitude.
>
> I would sooner believe the network had a mixture of DHCP and
> static assignments, and perhaps a duplicate address was affecting
> things.
>
> If it's GbE, a certain amount of defectivity can be removed
> by the PHY during negotiation. It could drop the interface
> to 100BT, if a "lucky choice" is made for the wiring defect.
> I don't think MDI/MDIX can fix everything. It's sorta like
> PCI express, that can correct a number of faults, simply
> by automatically turning off some of the lanes and using
> the remaining lanes. A person might never know, that
> lane 9 on the x16 video card slot, had been busted for the last
> five years. There's no warning in software.
>
> One of the reasons for debugging stuff like this networking
> problem, is to build your catalog of experience.
>
> The Marvell NIC on one of the motherboards here, has a TDR on it,
> and it can tell you "open, short, matched" on each of the four
> pairs. You turn off the power on your Switch, so the transformers
> are quiescent, and the Marvell NIC on the PC sends pulses down the line,
> to evaluate the wiring. But that motherboard died, and my
> attempts over the years to buy a standalone PCIe card, failed
> to work out. One box from the computer store, said Marvell
> on the outside, but a RealTek was inside. so now I have
> no TDR to use.
>
> There is still a copy of the Virtual Cable Tester whitepaper
> at the bottom of this page. It has a couple pictures of
> waveforms. And the VCT can give an estimate of how many feet
> away the defect is. I don't know if it was stated anywhere,
> as to the measurement uncertainty (+/- nanoseconds or feet).
>
> https://www.teklib.com/library/vct-marvell-virtual-cable-tester-technology-for-gigabit-networks-white-paper/
>
>
>    Paul

Sounds slick.
When I come across Ethernet cable problems, I call in
the big guns.

On 3/25/22 08:21, Jonathan N. Little wrote:

> Okay this relates to your "confusion" between hub and switch. Hub,
> switch, router, are devices in increasing "intelligence" in routing. A
> hub it the "dumbest" of all where any traffic it receives on the network
> is simply broadcasted on all ports. It is why a hub can create a noisy
> LAN, but can also be helpful in diagnostics because you can see all the
> communication on the network. I have an old hub on the shelf just for
> such applications. A switch is a hub with extra processing to register
> MAC addresses of connected devices on a network so when requests are
> made they are not broadcasted over all port but directed only to the
> port with destination's recorded MAC address. More efficient and allows
> FULL DUPLEX communication between devices. It is also why, your printer
> issue may have been illustrative, a switch's MAC table can get corrupted
> or obsolete which can cause issues. Noted with older, cheaper switches
> where power blips or switching cables too much would cause nodes not to
> work and required power cycling the switch to resolve. Of course lastly
> the router with more "intelligence" to handle connection between devices
> on different networks with NAT.
>

Hi Jonathan,

No argument there.

My use of the word "Hub" is generic. Both are "hubs".

And it is also proper English:
https://www.merriam-webster.com/dictionary/hubs

2a : a center of activity : focal point
c : a central device that connects multiple
computers on a single network

The old style "Layer 1 Network Hub" is a hub.

The new, GREATLY IMPROVED "Layer 2 MAC bridge
switching hub" is also a hub.

The "Layer 2 Hub" works way, way better than the
old "Layer 1 Hubs". Good lord, do you remember
the "coax networks"? Loved when twisted pair hit.

But they are still BOTH hubs: "a central device
that connects multiple computers on a single
network".

I have also noticed that the early Layer 2 hubs
had to be power cycled a lot. Have not noticed
it for several years though.

We now have Layer 3 and 4 hubs too. Never used
one. My customers are all small businesses and
don't need such a thing.

Once, no one could get decent Internet due to
someone video streaming over bonded DSL. Physical
threats by other employees did the trick. I
suppose Layer 3 or Layer 4 hubs could have
programmed him out but I don't know how the work.

-T

On 3/24/22 23:53, ...w¡ñ§±¤ñ wrote:
> T wrote:
>> Hi All,
>>
>> Had a weird on e yesterday.
>>
>> I installed a computer at a new location for a customer.
>> The network cable from the wall worked fine
>> directly into the computer.  But then I plugged it
>> into a little 5 port hub.  Then no worky.  A
>> different brand hub later and still no worky.
>> Hmmmm.
>>
>> Well the master hub the wall cable was plugged into was
>> across the room, so I strung a 25' cable from the
>> little hub to the master hub.  Worked!
>>
>> Moral of the story.  Please do not use electricians
>> to string data cable(s).  They always screw something up.
>>
>> -T
>
> :) When did the electricians install the wiring to the wall cable outlet?
>
>
All the time.
And the bozo put everything into a wall panel
so crowded you could not get at the power
cable to cycle the cable modem. And no
markings on the outlets or the cables.
Who cares what goes where.
And, of cource, the wall panel has a
locked door on it to make sure EVERYTHING
inside cooks to a nice crispy powder when
the hot weather hits. Zero circulation.
Patch panel? What's a patch panel?
Took my breath away.

T wrote:
> On 3/24/22 23:53, ...w¡ñ§±¤ñ wrote:
>> T wrote:
>>> Hi All,
>>>
>>> Had a weird on e yesterday.
>>>
>>> I installed a computer at a new location for a customer.
>>> The network cable from the wall worked fine
>>> directly into the computer.  But then I plugged it
>>> into a little 5 port hub.  Then no worky.  A
>>> different brand hub later and still no worky.
>>> Hmmmm.
>>>
>>> Well the master hub the wall cable was plugged into was
>>> across the room, so I strung a 25' cable from the
>>> little hub to the master hub.  Worked!
>>>
>>> Moral of the story.  Please do not use electricians
>>> to string data cable(s).  They always screw something up.
>>>
>>> -T
>>
>> :) When did the electricians install the wiring to the wall cable outlet?
>>
>>
>
> All the time.

How long ago?
Days, Weeks, Years, ???

--
....w¡ñ§±¤ñ

On 3/25/22 16:42, ...w¡ñ§±¤ñ wrote:
> T wrote:
>> On 3/24/22 23:53, ...w¡ñ§±¤ñ wrote:
>>> T wrote:
>>>> Hi All,
>>>>
>>>> Had a weird on e yesterday.
>>>>
>>>> I installed a computer at a new location for a customer.
>>>> The network cable from the wall worked fine
>>>> directly into the computer.  But then I plugged it
>>>> into a little 5 port hub.  Then no worky.  A
>>>> different brand hub later and still no worky.
>>>> Hmmmm.
>>>>
>>>> Well the master hub the wall cable was plugged into was
>>>> across the room, so I strung a 25' cable from the
>>>> little hub to the master hub.  Worked!
>>>>
>>>> Moral of the story.  Please do not use electricians
>>>> to string data cable(s).  They always screw something up.
>>>>
>>>> -T
>>>
>>> :) When did the electricians install the wiring to the wall cable
>>> outlet?
>>>
>>>
>>
>> All the time.
>
> How long ago?
> Days, Weeks, Years, ???
>
>
Sorry, I don't have that at hand. I do
come in lot after electricians and have
to call in professionals to fix their stuff.
How many times that has happened, I could not
venture a guess. Probably less than 10 times
over as many years. Keep in mind am the supreme
generalist. Seldom do I see two problems alike.
Sometimes I do though.

On Fri, 25 Mar 2022 11:21:32 -0400, "Jonathan N. Little"
<lws4art@gmail.com> wrote:

<snip>
>
>Okay this relates to your "confusion" between hub and switch. Hub,
>switch, router, are devices in increasing "intelligence" in routing. A
>hub it the "dumbest" of all where any traffic it receives on the network
>is simply broadcasted on all ports. It is why a hub can create a noisy
>LAN, but can also be helpful in diagnostics because you can see all the
>communication on the network. I have an old hub on the shelf just for
>such applications. A switch is a hub with extra processing to register
>MAC addresses of connected devices on a network so when requests are
>made they are not broadcasted over all port but directed only to the
>port with destination's recorded MAC address. More efficient and allows
>FULL DUPLEX communication between devices. It is also why, your printer
>issue may have been illustrative, a switch's MAC table can get corrupted
>or obsolete which can cause issues. Noted with older, cheaper switches
>where power blips or switching cables too much would cause nodes not to
>work and required power cycling the switch to resolve. Of course lastly
>the router with more "intelligence" to handle connection between devices
>on different networks with NAT.

Thanks for trying. I don't think it worked but it was a great effort.
Maybe others will benefit.