$ ethtool eth3
Settings for eth3:
        Supported ports: [ TP ]
        Supported link modes:   10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Full
        Supported pause frame use: No
        Supports auto-negotiation: Yes
        Advertised link modes:  10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Full
        Advertised pause frame use: No
        Advertised auto-negotiation: Yes
        Speed: 100Mb/s
        Duplex: Full
        Port: Twisted Pair
        PHYAD: 1
        Transceiver: internal
        Auto-negotiation: on
        MDI-X: on (auto)
Cannot get wake-on-lan settings: Operation not permitted
        Current message level: 0x00000007 (7)
                               drv probe link
        Link detected: yes

$ ifconfig
eth3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.5.102  netmask 255.255.255.0  broadcast 192.168.5.255
        inet6 2002:640f:52d5:1234:7296:6e02:b804:3dba  prefixlen 64  scopeid 0x0<global>
        inet6 2002:640f:52d5:1234:292c:703c:88d7:21a4  prefixlen 64  scopeid 0x0<global>
        inet6 fe80::105c:6f14:dbe5:8988  prefixlen 64  scopeid 0x20<link>
        ether 38:2c:4a:6e:19:5d  txqueuelen 1000  (Ethernet)
        RX packets 14220  bytes 9620567 (9.6 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 11754  bytes 1344126 (1.3 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        device interrupt 20  memory 0xfb200000-fb220000

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1  (Local Loopback)
        RX packets 3923  bytes 879984 (879.9 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 3923  bytes 879984 (879.9 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

tun0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST>  mtu 1500
        inet 10.100.10.1  netmask 255.255.255.255  destination 10.100.10.2
        inet6 fe80::773c:31ef:206d:d729  prefixlen 64  scopeid 0x20<link>
        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 100  (UNSPEC)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 3  bytes 144 (144.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0