ifconfig
[root@localhost ~]# ifconfig
ens33: flags=4163 mtu 1500
inet 192.168.223.129 netmask 255.255.255.0 broadcast 192.168.223.255
inet6 fe80::e537:3c3b:9ce6:ce37 prefixlen 64 scopeid 0x20
ether 00:0c:29:ae:46:bc txqueuelen 1000 (Ethernet)
RX packets 3787 bytes 260761 (254.6 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 873 bytes 149916 (146.4 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73 mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10
loop txqueuelen 1000 (Local Loopback)
RX packets 68 bytes 5920 (5.7 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 68 bytes 5920 (5.7 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
ifconfig 配置接口ip
[root@localhost ~]# ifconfig lo
lo: flags=73 mtu 65536
inet 192.168.1.1 netmask 255.255.0.0
inet6 ::1 prefixlen 128 scopeid 0x10
loop txqueuelen 1000 (Local Loopback)
RX packets 72 bytes 6272 (6.1 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 72 bytes 6272 (6.1 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
[root@localhost ~]# ifconfig lo 127.0.0.1/8 promisc up
[root@localhost ~]# ifconfig lo
lo: flags=329 mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10
loop txqueuelen 1000 (Local Loopback)
RX packets 72 bytes 6272 (6.1 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 72 bytes 6272 (6.1 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
[root@localhost ~]# ifconfig lo -promisc
[root@localhost ~]# ifconfig lo
lo: flags=73 mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10
loop txqueuelen 1000 (Local Loopback)
RX packets 72 bytes 6272 (6.1 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 72 bytes 6272 (6.1 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
route
查看路由表
[root@localhost ~]# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
default gateway 0.0.0.0 UG 100 0 0 ens33
192.168.223.0 0.0.0.0 255.255.255.0 U 100 0 0 ens33
[root@localhost ~]# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 192.168.223.2 0.0.0.0 UG 100 0 0 ens33
192.168.223.0 0.0.0.0 255.255.255.0 U 100 0 0 ens33
添加路由
[root@localhost ~]# route add -net 172.16.0.0/16 dev lo
[root@localhost ~]# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
default gateway 0.0.0.0 UG 100 0 0 ens33
172.16.0.0 0.0.0.0 255.255.0.0 U 0 0 0 lo
192.168.223.0 0.0.0.0 255.255.255.0 U 100 0 0 ens33
删除路由
[root@localhost ~]# route del -net 172.16.0.0/16
[root@localhost ~]# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
default gateway 0.0.0.0 UG 100 0 0 ens33
192.168.223.0 0.0.0.0 255.255.255.0 U 100 0 0 ens33
netstat
-r显示路由
[root@localhost ~]# netstat -rn
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
0.0.0.0 192.168.223.2 0.0.0.0 UG 0 0 0 ens33
192.168.223.0 0.0.0.0 255.255.255.0 U 0 0 0 ens33
[root@localhost ~]# netstat -r
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
default gateway 0.0.0.0 UG 0 0 0 ens33
192.168.223.0 0.0.0.0 255.255.255.0 U 0 0 0 ens33
-t -u 查看tcp udp链接
[root@localhost ~]# netstat -tua
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 0.0.0.0:ssh 0.0.0.0:* LISTEN
tcp 0 0 localhost:smtp 0.0.0.0:* LISTEN
tcp 0 0 localhost.localdoma:ssh 192.168.223.1:sstsys-lm ESTABLISHED
tcp 0 52 localhost.localdoma:ssh 192.168.223.1:14472 ESTABLISHED
tcp6 0 0 [::]:ssh [::]:* LISTEN
tcp6 0 0 localhost:smtp [::]:* LISTEN
udp 0 0 0.0.0.0:bootpc 0.0.0.0:*
udp 0 0 localhost:323 0.0.0.0:*
udp6 0 0 localhost:323 [::]:*
[root@localhost ~]# netstat -tuan
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN
tcp 0 0 192.168.223.129:22 192.168.223.1:1692 ESTABLISHED
tcp 0 52 192.168.223.129:22 192.168.223.1:14472 ESTABLISHED
tcp6 0 0 :::22 :::* LISTEN
tcp6 0 0 ::1:25 :::* LISTEN
udp 0 0 0.0.0.0:68 0.0.0.0:*
udp 0 0 127.0.0.1:323 0.0.0.0:*
udp6 0 0 ::1:323 :::*
-l -p
[root@localhost ~]# netstat -tnlp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 6428/sshd
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 6571/master
tcp6 0 0 :::22 :::* LISTEN 6428/sshd
tcp6 0 0 ::1:25 :::* LISTEN 6571/master
查看接口统计数据
[root@localhost ~]# netstat -i
Kernel Interface table
Iface MTU RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg
ens33 1500 7974 0 0 0 2696 0 0 0 BMRU
lo 65536 72 0 0 0 72 0 0 0 LRU
[root@localhost ~]# netstat -Iens33
Kernel Interface table
Iface MTU RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg
ens33 1500 7994 0 0 0 2708 0 0 0 BMRU
ifdown ifup
[root@localhost ~]# ifdown lo
[root@localhost ~]# ifconfig lo
lo: flags=8 mtu 65536
loop txqueuelen 1000 (Local Loopback)
RX packets 72 bytes 6272 (6.1 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 72 bytes 6272 (6.1 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
[root@localhost ~]# ifup lo
[root@localhost ~]# ifconfig lo
lo: flags=73 mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10
loop txqueuelen 1000 (Local Loopback)
RX packets 72 bytes 6272 (6.1 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 72 bytes 6272 (6.1 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
hostname
[root@localhost ~]# hostname
localhost.localdomain
[root@localhost ~]# hostnamectl
Static hostname: localhost.localdomain
Icon name: computer-vm
Chassis: vm
Machine ID: 5f47125a1faf4b438a9b7aec3758819e
Boot ID: a7b873fd1eb64e56a8f1bd3d06e31964
Virtualization: vmware
Operating System: CentOS Linux 7 (Core)
CPE OS Name: cpe:/o:centos:centos:7
Kernel: Linux 3.10.0-957.el7.x86_64
Architecture: x86-64
[root@localhost ~]# uname
Linux
[root@localhost ~]# uname -a
Linux localhost.localdomain 3.10.0-957.el7.x86_64 #1 SMP Thu Nov 8 23:39:32 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
/etc/sysconfig/network
HOSTNAME=
DNS配置
/etc/resolv.conf
[root@localhost ~]# cat /etc/resolv.conf
# Generated by NetworkManager
search localdomain
nameserver 192.168.223.2
ip link
show / list
[root@localhost ~]# ip link show
1: lo: mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: ens33: mtu 1500 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
link/ether 00:0c:29:ae:46:bc brd ff:ff:ff:ff:ff:ff
set [down/up name multicast on/off...]
[root@localhost ~]# ip link set lo down
[root@localhost ~]# ip link list lo
1: lo: mtu 65536 qdisc noqueue state DOWN mode DEFAULT group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
[root@localhost ~]# ip link set lo up && ip link list lo
1: lo: mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
ip address
add
[root@localhost ~]# ip addr add 172.16.0.1/16 dev lo
[root@localhost ~]# ip addr show lo
1: lo: mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet 172.16.0.1/16 scope global lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
delete
[root@localhost ~]# ip addr delete 172.16.0.1/16 dev lo && ip addr show
1: lo: mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
flush
[root@localhost ~]# ip addr flush lo && ip addr show lo
1: lo: mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
ip route
ip route add
ip route delete
ss命令
[root@localhost ~]# ss -tm
State Recv-Q Send-Q Local Address:Port Peer Address:Port
ESTAB 0 52 192.168.223.129:ssh 192.168.223.1:4244
skmem:(r0,rb369280,t0,tb87040,f1792,w2304,o0,bl0,d0)
[root@localhost ~]# ss -to
State Recv-Q Send-Q Local Address:Port Peer Address:Port
ESTAB 0 52 192.168.223.129:ssh 192.168.223.1:4244 timer:(on,238ms,0)
配置文件
接口配置文件：/etc/sysconfig/network-scripts/ifcfg-IFACE
路由配置文件：/etc/sysconfig/network-scripts/route-IFACE
nmcli
[root@localhost ~]# nmcli device show lo
GENERAL.DEVICE: lo
GENERAL.TYPE: loopback
GENERAL.HWADDR: 00:00:00:00:00:00
GENERAL.MTU: 65536
GENERAL.STATE: 10 (unmanaged)
GENERAL.CONNECTION: --
GENERAL.CON-PATH: --
IP4.ADDRESS[1]: 127.0.0.1/8
IP4.GATEWAY: --
IP6.GATEWAY: --