how to figured out the negotiated speed for network card

ethtool eth0

Settings for eth0:

        Supported ports: [ TP ]

        Supported link modes:   1000baseT/Full 

        Supports auto-negotiation: No

        Advertised link modes:  Not reported

        Advertised pause frame use: No

        Advertised auto-negotiation: No

        Speed: 1000Mb/s

        Duplex: Full

        Port: Twisted Pair

        PHYAD: 0

        Transceiver: internal

        Auto-negotiation: off

        MDI-X: Unknown

        Link detected: yes