How to check whether eth0 has connection speed 10Mbit, 100Mbit or 1Gbit? I tried ethtool, but it says No data available. I also tried dmesg | grep -i duplex and it's empty.[root@dioptase ~]# lspci00:0a.0 Ethernet controller: Digital Equipment Corporation DECchip 21140 [FasterNet] (rev 20)[root@dioptase ~]# ethtool eth0Settings for eth0:No data available[root@dioptase ~]# ethtool -i eth0driver: tulipversion: 1.1.15firmware-version:bus-info: 0000:00:0a.0[root@dioptase ~]# ifconfig eth0eth0      Link encap:Ethernet  HWaddr 00:15:5D:6F:1E:09          inet addr:192.168.140.106  Bcast:192.168.140.255  Mask:255.255.255.0          inet6 addr: 2a00:1120:0:1002:215:5dff:fe6f:1e09/64 Scope:Global          inet6 addr: fe80::215:5dff:fe6f:1e09/64 Scope:Link          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1          RX packets:95671897 errors:6 dropped:0 overruns:0 frame:6          TX packets:16524440 errors:0 dropped:0 overruns:0 carrier:0          collisions:0 txqueuelen:1000          RX bytes:23933711964 (22.2 GiB)  TX bytes:19761966217 (18.4 GiB)          Interrupt:9 Base address:0xe000
Determine ethernet speed in RHEL 6
linux;ethernet;network interface