How To: Check Network Connectivity on CentOS/Linux
Very often I need to check my servers to see they are using full duplex or see what the status is of the network interface. Here are a few commands I use to check that.
1. Check interface speed and duplex: mii-tool eth0, or just mii-tool and it will show all installed interfaces
2. Get the supported interface option list for possible settings: ethtool eth0 or ethtool eth1, etc
3. See supported options: mii-tool -v