Linux Network-related commands and linux Network-related commands
Ifconfig
Ifconfig is the command to view the NIC in centos6. In centos7, you must install the net-tools package before using it?
Nic configuration file:/etc/sysconfig/network-scripts/ifcfg-ens33?
Command: ifconfig
[root@shuai-01 ~]# ifconfigens33: flags=4163
mtu 1500 inet 192.168.176.135 netmask 255.255.255.0 broadcast 192.168.176.255 inet6 fe80::16f5:8ee4:b971:e6fb prefixlen 64 scopeid 0x20
ether 00:0c:29:a1:0e:2c txqueuelen 1000 (Ethernet) RX packets 236 bytes 23351 (22.8 KiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 216 bytes 25791 (25.1 KiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0lo: flags=73
mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10
loop txqueuelen 1 (Local Loopback) RX packets 68 bytes 5524 (5.3 KiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 68 bytes 5524 (5.3 KiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
Disable NIC:
ifdown ens33
Enable NIC:
ifup ens33
When the network card is disabled, it cannot be remotely connected. Especially when you are using this Nic.
To restart an Eni:
[Root @ shuai-01 ~] # Ifdown ens33 & ifup ens33 disconnect the device 'ens33 '. Successfully activated connections (D-Bus activation path:/org/freedesktop/NetworkManager/ActiveConnection/1)
To restart the network service:
service restrat network
Set multiple ip addresses for one network card
One Nic can have multiple IP addresses. How can I set a virtual IP address for one Nic?
Enter the NIC configuration file and copy a configuration file
[root@shuai-01 ~]# cd /etc/sysconfig/network-scripts/[root@shuai-01 network-scripts]# lsifcfg-ens33 ifdown-ppp ifup-ib ifup-Teamifcfg-lo ifdown-routes ifup-ippp ifup-TeamPortifdown ifdown-sit ifup-ipv6 ifup-tunnelifdown-bnep ifdown-Team ifup-isdn ifup-wirelessifdown-eth ifdown-TeamPort ifup-plip init.ipv6-globalifdown-ib ifdown-tunnel ifup-plusb network-functionsifdown-ippp ifup ifup-post network-functions-ipv6ifdown-ipv6 ifup-aliases ifup-pppifdown-isdn ifup-bnep ifup-routesifdown-post ifup-eth ifup-sit[root@shuai-01 network-scripts]# cp ifcfg-ens33 ifcfg-ens33:0
Vi new configuration file change information: NAME, DEVICE, IPADDR, GATEWAY, DNS
NAME=ens33:0DEVICE=ens33:0IPADDR=192.168.176.150
GATEWAY, DNS do not
Restart the NIC after saving and exiting:
[root@shuai-01 network-scripts]# ifdown ens33 && ifup ens33
View the connection status of the ENI
Command: mii-tool
[root@shuai-01 network-scripts]# mii-tool ens33ens33: negotiated 1000baseT-FD flow-control, link ok
Link OK indicates the connected network cable?
Command: ethtool
[root@shuai-01 network-scripts]# ethtool ens33Settings for ens33: 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: 1000Mb/s Duplex: Full Port: Twisted Pair PHYAD: 0 Transceiver: internal Auto-negotiation: on MDI-X: off (auto) Supports Wake-on: d Wake-on: d Current message level: 0x00000007 (7) drv probe link Link detected: yes
Link detected: yes indicates the network connection.
Change Host Name
Command: hostnamectl?
Command Format: hostnamectl set-hostname Host Name
Host Name configuration file:/etc/hostname
Set dns
Dns configuration file:/etc/resolv. conf
View the dns configuration file:
[root@shuai-01 network-scripts]# cat /etc/resolv.conf # Generated by NetworkManagernameserver 119.29.29.29
Can I change the dns in the NIC configuration file or in the dns configuration file?
Add:
DNS2=8.8.8.8
In the dns configuration file (temporary ):
nameserver 8.8.8.8
The custom dns domain name takes effect on the local machine. After the definition, you do not need to enter the dns resolution domain name .?
Configuration File:/etc/hosts
Add a DNS domain name:
[root@shuai-01 network-scripts]# vim /etc/hosts
Add DNS domain name:
192.168.172.3 www.baidu.com193.168.176.56 www.qq.com www.hao123.com
Ping:
[root@shuai-01 network-scripts]# ping www.baidu.comPING www.baidu.com (192.168.172.3) 56(84) bytes of data.[root@shuai-01 network-scripts]# ping www.qq.comPING www.qq.com (193.168.176.56) 56(84) bytes of data.
- One IP address can be followed by multiple domain names
- One row can have only one IP Address