[Kazun]

Код:

PS > Get-NetAdapter | SELECT name, status, linkspeed, fullduplex

name                         Status       LinkSpeed fullduplex
----                         ------       --------- ----------
Ethernet 4                   Up           100 Mbps        True
VirtualBox Host-Only Network Up           1 Gbps          True
Ethernet 3                   Disconnected 1.1 Gbps

Если ОС ниже 8,то :

Код:

PS > Get-WmiObject Win32_NetworkAdapter -Filter "Speed IS NOT NUll"| Select Name, Speed, NetEnabled

Name                                               Speed NetEnabled
----                                               ----- ----------
VirtualBox Host-Only Ethernet Adapter         1000000000       True
Microsoft ISATAP Adapter                          100000
Microsoft ISATAP Adapter #2                       100000
Realtek RTL8139/810x Family Fast Ethernet NIC 1073741824      False
Realtek PCIe GBE Family Controller             100000000       True

Если Duplex нужен обязательно - http://itknowledgeexchange.techtarge...ed-and-duplex/