How can I know if a given wired connection is in full or half duplex?
I know how to check the settings but most adapters are set to auto-
negotiate and I don't know what was negotiated. Some switches will
tell you on their status lights but there's got to be a way to query a
system and get it to say if it's running in full or half. I"ve
searched everywhere and just find tons of answers about how to change
settings on a card. That doesn't give me a way to check the current
state. Thanks.

njem <(E-Mail Removed)> wrote in
news:d1be08d7-89e6-4bcc-980c-(E-Mail Removed)
m:

> How can I know if a given wired connection is in full or half
> duplex? I know how to check the settings but most adapters are set
> to auto- negotiate and I don't know what was negotiated. Some
> switches will tell you on their status lights but there's got to
> be a way to query a system and get it to say if it's running in
> full or half. I"ve searched everywhere and just find tons of
> answers about how to change settings on a card. That doesn't give
> me a way to check the current state. Thanks.
>

That detail is buried in the driver details. AFAIK, there is no
standard Windows driver interface that extracts this information from
whatever manufacturer's network card/driver that you use. Having said
that, I believe that *some* manufacturer's drivers generate a System
Log message declaring this information that you can look up using the
Event Viewer (Start -> Run -> "eventvwr.msc"). For example, my
computer has an Intel network card/chipset and I see the following
Information message in my System Event log at startup:

Intel(R) 82567LM Gigabit Network Connection Link has been established:
100Mbps full duplex.

HTH,
John

> *For example, my
> computer has an Intel network card/chipset and I see the following
> Information message in my System Event log at startup:
>
> Intel(R) 82567LM Gigabit Network Connection Link has been established:
> 100Mbps full duplex.

Excellent idea. I just checked a few systems and most had some similar
report. One with an Intel NIC gives a generic report about connecting
but no details.

Thanks.