1. Add yourself (sa) to the sudoers configuration file for easy access
vim /etc/ sudoers edit file (some centOS versions do not have vim command, just use vi) Find the [root ALL = (ALL) ALL] statement and add it below: sa ALL=(ALL) ALL Special note: The sudo command can only be used after sa is added to the sudoers configuration file.
2. Internet
ifconfig View the network status to see how many network cards this server can put at most, such as eth0, eth1, eth2...
ifup eth0 activate the network card (eth0 represents the first network card) This is a shorthand, if it does not work, you can use the following instead
ifconfig eth0 down stop the network card eth0
ifconfig eth0 up start the network card eth0
sudo ifup eth0 Use the sudo command to temporarily have administrator privileges to activate the network card
Check if there is a network card connected: ethtool eth0; eth0 is the name of the network card. When the Link detecte in the following information is yes, it means that the network card is connected, and Speed indicates the speed of the network card.
[root@lingdian03 /]# ethtool eth0 Settings for eth0: Supported ports: [ TP ] Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Full Supported pause frame use: Symmetric Supports auto-negotiation: Yes Advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Full Advertised pause frame use: Symmetric Advertised auto-negotiation: Yes Speed: Unknown! Duplex: Unknown! (255) Port: Twisted Pair PHYAD: 1 Transceiver: internal Auto-negotiation: on MDI-X: Unknown Supports Wake-on: pumbg Wake-on: g Current message level: 0x00000007 (7) drv probe link Link detected: no
3、ping
Ping www.baidu.com to check whether the network is smooth, ping both domain name and ip
Ctrl + C key combination terminates most commands (can be used to exit the ping state)