linux 中netstat命令

linux 中 netstat命令用于统计网络相关信息。

常用命令示例：

1、查看IP

[root@rhelpc1 test]# netstat | head       ## 查看本机IP
Active Internet connections (w/o servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State
tcp        0     64 192.168.3.25:ssh        192.168.3.4:nbdb        ESTABLISHED
Active UNIX domain sockets (w/o servers)
Proto RefCnt Flags       Type       State         I-Node   Path
unix  2      [ ]         DGRAM                    12809    @/org/freedesktop/systemd1/notify
unix  5      [ ]         DGRAM                    7604     /run/systemd/journal/socket
unix  26     [ ]         DGRAM                    7606     /dev/log
unix  2      [ ]         DGRAM                    12998    /run/systemd/shutdownd
unix  3      [ ]         STREAM     CONNECTED     24490

2、查看所有网卡

[root@rhelpc1 test]# netstat -i       ## 网卡列表
Kernel Interface table
Iface      MTU    RX-OK RX-ERR RX-DRP RX-OVR    TX-OK TX-ERR TX-DRP TX-OVR Flg
eno16777  1500     4051      0      0 0          2483      0      0      0 BMRU
lo       65536        6      0      0 0             6      0      0      0 LRU

3、统计各个网络连接状态的个数

[root@rhelpc1 test]# netstat -a | awk '/^tcp/ {++a[$NF]} END {for(i in a) print i, a[i]}'   ## 统计各个网络连接状态的个数
LISTEN 10
ESTABLISHED 1

4、查看程序运行的端口

[root@rhelpc1 test]# netstat -ap | grep ssh
tcp        0      0 0.0.0.0:ssh             0.0.0.0:*               LISTEN      1667/sshd
tcp        0     64 192.168.3.25:ssh        192.168.3.4:nbdb        ESTABLISHED 2683/sshd: root@pts
tcp6       0      0 [::]:ssh                [::]:*                  LISTEN      1667/sshd
unix  2      [ ACC ]     STREAM     LISTENING     27177    2062/gnome-keyring-  /run/user/0/keyring-c7kFmk/ssh   ## 27177
unix  2      [ ACC ]     STREAM     LISTENING     26735    2216/ssh-agent       /tmp/ssh-oTQohO1JHPul/agent.2064
unix  3      [ ]         STREAM     CONNECTED     23252    1667/sshd
unix  2      [ ]         DGRAM                    29079    2683/sshd: root@pts

5、查看端口是否被占用

[root@rhelpc1 test]# netstat -nlp | grep 27177     ## 查看端口是否被占用
unix  2      [ ACC ]     STREAM     LISTENING     27177    2062/gnome-keyring-  /run/user/0/keyring-c7kFmk/ssh

参考：https://blog.csdn.net/qq_45988641/article/details/117365096