Verify the speed of my Network Cards in Linux

How to tell the network speed of network cards in Linux?

CentOS 7

Find the network cards:

ip addr

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: ens160: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
    link/ether 00:0c:29:d5:dc:4a brd ff:ff:ff:ff:ff:ff
    inet 216.55.xxx.xxx/24 brd 216.55.169.255 scope global ens160
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fed5:dc4a/64 scope link
       valid_lft forever preferred_lft forever
3: ens192: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
    link/ether 00:0c:29:d5:dc:54 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.101/24 brd 192.168.1.255 scope global ens192
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fed5:dc54/64 scope link
       valid_lft forever preferred_lft forever

Ethtool

# ethtool ens160
Settings for ens160:
        Supported ports: [ TP ]
        Supported link modes:   1000baseT/Full
                                10000baseT/Full
        Supported pause frame use: No
        Supports auto-negotiation: No
        Advertised link modes:  Not reported
        Advertised pause frame use: No
        Advertised auto-negotiation: No
        Speed: 10000Mb/s
        Duplex: Full
        Port: Twisted Pair
        PHYAD: 0
        Transceiver: internal
        Auto-negotiation: off
        MDI-X: Unknown
        Supports Wake-on: uag
        Wake-on: d
        Link detected: yes

# ethtool ens160 | grep Speed
        Speed: 10000Mb/s

Script:

for i in $(netstat -i | cut -f1 -d" " | tail -n+3) ; do echo "$i: $(ethtool "$i" | grep Speed | sed 's/Speed://g')" ; done

cat /sys/class/net/<interface>/speed

# cat /sys/class/net/ens160/speed
10000

Above would be in MB.

DMESG

# dmesg |grep eth0
[0.932304] vmxnet3 0000:03:00.0 eth0: NIC Link is Up 10000 Mbps