Can get 10mbit/s networking but not 100mbit/s

[Sim]

I have 2 PC's on a LAN. One of them is a midi tower case a Realtek 8139, the
other is a micro-ATX with an onboard NVidia networking controller. I can
connect both PCs at 10mbit/s half duplex just fine but I cannot connect them
properly at 100mbit/s half duplex. I have even searched
PracticallyNetworked.com and found nothing that relates to this problem.

With the main PC using the Realtek 8139 we had an older PC ages ago on the
other end, also using an 8139. This worked fine at 100mbit/s half duplex, so
this rules out any physical problem

At the moment it is on 10mbit/s half duplex but I want 100mbit/s. How can I
sort this out?

Sim

 

[CWatters]

I have 2 PC's on a LAN. One of them is a midi tower case a Realtek 8139, the
other is a micro-ATX with an onboard NVidia networking controller. I can
connect both PCs at 10mbit/s half duplex just fine but I cannot connect them
properly at 100mbit/s half duplex. I have even searched
PracticallyNetworked.com and found nothing that relates to this problem.

With the main PC using the Realtek 8139 we had an older PC ages ago on the
other end, also using an 8139. This worked fine at 100mbit/s half duplex, so
this rules out any physical problem

It sounds lijke the Realtek 8139 is happy. Check that the NVidia networking
controller in the micro ATX supports 100Mbit?

 

[Lanwench [MVP - Exchange]]

In

I have 2 PC's on a LAN. One of them is a midi tower case a Realtek
8139, the other is a micro-ATX with an onboard NVidia networking
controller. I can connect both PCs at 10mbit/s half duplex just fine
but I cannot connect them properly at 100mbit/s half duplex. I have
even searched PracticallyNetworked.com and found nothing that relates
to this problem.
With the main PC using the Realtek 8139 we had an older PC ages ago
on the other end, also using an 8139. This worked fine at 100mbit/s
half duplex, so this rules out any physical problem

At the moment it is on 10mbit/s half duplex but I want 100mbit/s. How
can I sort this out?

Sim

Have you tried downloading a newer driver for the NIC?

 

[CWatters]

I'm sure you have already but..

Check the Device Manager -> Network Adapters -> Right click your network
cards and select "Properties" -> Advanced tab -> port speed set to "auto"

If that doesn't work set it to 100.

 

[Sim]

It sounds lijke the Realtek 8139 is happy. Check that the NVidia
networking
controller in the micro ATX supports 100Mbit?

It does but it won't use 100Mbps with the Realtek 8139 properly.

 

[Sim]

I'm sure you have already but..

Check the Device Manager -> Network Adapters -> Right click your network
cards and select "Properties" -> Advanced tab -> port speed set to "auto"

If that doesn't work set it to 100.

I did that. Still no luck.

Sim

 

[Mak]

can you tell us what is in between 2 nics? e.g., cables category, hub /
switch (list models), link / duplex settings.

 

[CWatters]

I did that. Still no luck.

How long is the cable between the two and are there any hubs or routers in
there? Have you tried another cable (not that I really expect that to make
much difference).

When you say it doesn't work... do you mean it defaults to 10Mbit or that
it's unreliable? Any error messages? Events in the Event logs?

 

[cquirke (MVP Windows shell/user)]

I have 2 PC's on a LAN. One of them is a midi tower case a Realtek 8139, the
other is a micro-ATX with an onboard NVidia networking controller. I can
connect both PCs at 10mbit/s half duplex just fine but I cannot connect them
properly at 100mbit/s half duplex. I have even searched
PracticallyNetworked.com and found nothing that relates to this problem.

With the main PC using the Realtek 8139 we had an older PC ages ago on the
other end, also using an 8139. This worked fine at 100mbit/s half duplex, so
this rules out any physical problem

At the moment it is on 10mbit/s half duplex but I want 100mbit/s. How can I
sort this out?

Firstly, make sure that both adapters (as well as any hubs, routers or
switches in between) are 100Mbits-capable.

Secondly, make sure the cabling grade is within spec, including max
length and midway connectoins.

Thirdly, if using crossover cable to avoid the need for a hub, switch
or router, check the pin routing and quality of the connections (look
out for wires that stop short of the copper punch contacts within the
plugs - that's bitten my ass a few times). Partially-correct
crossover wiring may work at 10Mbs but not 100Mbs; I don't know the
technology well enough to be sure about that, though.

Finally, check the adapter's settings for anything that is locking
them down to the lower speed. Note that firmware-level changes can
cause XP to redetect the adapter and lose a Product Activation "life".

 

[Sim]

can you tell us what is in between 2 nics? e.g., cables category, hub /
switch (list models), link / duplex settings.

Cat 5E crossover cable, about 30m
No hubs or switches
Tried 100HD/FD on the RTL8139 and Nvidia but it didn't work, but 100HD works
ok on both computers with RTL8139s.

 

[Sim]

How long is the cable between the two and are there any hubs or routers in
there? Have you tried another cable (not that I really expect that to make
much difference).

When you say it doesn't work... do you mean it defaults to 10Mbit or that
it's unreliable? Any error messages? Events in the Event logs?

Its unreliable at 100Mbps. I get ping timeouts, starting with a few, then it
timeouts all the time.

Sim

 

[Sim]

Firstly, make sure that both adapters (as well as any hubs, routers or
switches in between) are 100Mbits-capable.

Done that

Secondly, make sure the cabling grade is within spec, including max
length and midway connectoins.

Done that

Thirdly, if using crossover cable to avoid the need for a hub, switch
or router, check the pin routing and quality of the connections (look
out for wires that stop short of the copper punch contacts within the
plugs - that's bitten my ass a few times). Partially-correct
crossover wiring may work at 10Mbs but not 100Mbs; I don't know the
technology well enough to be sure about that, though.

Finally, check the adapter's settings for anything that is locking
them down to the lower speed. Note that firmware-level changes can
cause XP to redetect the adapter and lose a Product Activation "life".

I don't know where to start, and the Realtek 8139 has more settings than the
NVidia.

 

[Mak]

ok, put both NICs in AUTO/AUTO for link/duplex.
if that doesn't work, one or both NICs are faulty or you have problem with
the cable because:
the only defined way how 100BaseTX devices determine their speed is AUTO.
Setting both or only one device manually is simply not mentioned
in the IEEE standard.

 

[cquirke (MVP Windows shell/user)]

Its unreliable at 100Mbps. I get ping timeouts, starting with a few, then it
timeouts all the time.

Ahhhhh.... so it works at 100Mbs, but badly.

There would be two broad reasons for this:
- signal quality
- signal propagation delay

All the fluff I mentioned about cable quality, length, number and
quality of connections etc. bears down with full force.

It's not only that poor quality will mess up the analog signals that
the card has to read into digital sense (and adjacent noisy mains
cables are another factor there).

It's also that delays induced by connections and cable length can
cause data to be placed on the cable after the adapter assumes a
collision is not in effect - i.e. a failure of the Ethernet collision
detection system. This is very much a factor of data speed, in that
the time window scales downwards as the speed increases - so "works
fine at 10Mbs, sucks at 100Mbs" would be typical mileage!

--------------- ----- ---- --- -- - - -

IRC is just multiplayer notepad.

 

[CWatters]

I think the OP should try a test with a 5 meter cable.

If that works reliably then that narrows down the problem greatly.I didn't
realise that 100Mbit used more than two logic levels....
http://www.pctechguide.com/29network_Gigabit_Ethernet.htm
Quote "Fast Ethernet achieves 100 Mbit/s operation by sending three-level
binary encoded symbols across the link at 125 Mbaud"

That's going to make it more prone to noise and crosstalk issues.

 

[CWatters]

I think the OP should try a test with a 5 meter cable.

If that works reliably then that narrows down the problem greatly.I didn't
realise that 100Mbit used more than two logic levels....
http://www.pctechguide.com/29network_Gigabit_Ethernet.htm
Quote "Fast Ethernet achieves 100 Mbit/s operation by sending three-level
binary encoded symbols across the link at 125 Mbaud"

That's going to make it more prone to noise and crosstalk issues.

If you have a suitable hub or router try inserting that in the 30 meter
cable somewhere near the micro ATX PC. Perhaps that PC hasn't got a very
good network driver. If that doesn't work try moving it to the other end of
the cable.