linux查看网络连接信息失败,【Linux 运维】查看网络连接状态信息之netstat和ss命令详解[转]...

转载自：https://www.cnblogs.com/yangleitao/p/9583280.html

一、netstat 常用命令详解

通过man netstat可以查看netstat的帮助信息：netstat 命令：用于显示各种网络相关信息，如网络连接，路由表，接口状态，无效连接，组播成员 等等。

netstat命令是net-tools软件包中的一员

[[email protected] ~]# netstat 选项

选项：

-a:　　列出系统中所有网络连接，包括已经连接的网络服务、监听的网络服务和Socket套接字

-t：　　列出TCP数据    -u：　　列出UDP数据

-l：　　列出正在监听的网络服务(不包含已经连接的网路服务)

-n：　　用端口显示服务，而不用服务名

-p：　　列出该服务的进程ID(PID)

示例一：netstat -tlunp

[[email protected] ~]# netstat -tlunp

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      1490/sshd

tcp        0      0 127.0.0.1:25            0.0.0.0:*               LISTEN      1989/master

tcp6       0      0 :::80                   :::*                    LISTEN      852/httpd

tcp6       0      0 :::22                   :::*                    LISTEN      1490/sshd

tcp6       0      0 ::1:25                  :::*                    LISTEN      1989/master

udp        0      0 127.0.0.1:323           0.0.0.0:*                           524/chronyd

udp6       0      0 ::1:323                 :::*                                524/chronyd

[[email protected] ~]#

实例二:使用netstat -an[[email protected] ~]# netstat -an

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      0 192.168.19.129:22       192.168.19.1:1108       ESTABLISHED

tcp        0      0 192.168.19.129:22       192.168.19.1:2301       ESTABLISHED

tcp6       0      0 :::80                   :::*                    LISTEN

tcp6       0      0 :::22                   :::*                    LISTEN

tcp6       0      0 ::1:25                  :::*                    LISTEN

udp        0      0 127.0.0.1:323           0.0.0.0:*

udp        0      0 192.168.19.129:39366    85.199.214.101:123      ESTABLISHED

udp        0      0 192.168.19.129:39060    85.199.214.100:123      ESTABLISHED

udp6       0      0 ::1:323                 :::*

Active UNIX domain sockets (servers and established)

Proto RefCnt Flags       Type       State         I-Node   Path

unix  2      [ ACC ]     STREAM     LISTENING     25859    /run/docker/libnetwork/2607d31c4b65ff68cf08c24cc6d5e4687dad654f9ec402872e98f8dcc79f448f.sock

unix  2      [ ACC ]     STREAM     LISTENING     24960    private/rewrite

执行结果，除了上文的参数之外，还有Socket内容：

二、ss命令详解

ss是Socket Statistics的缩写ss命令可以用来获取socket统计信息，它可以显示和netstat类似的内容。但是ss的优势在于它能够显示更详细的有关网络连接的状态信息，而比netstat更快速、更高效。

ss命令是iproute2软件包中的一员

使用场景一：查看当前服务器的网络连接数[[email protected] ~]# ss -s

Total: 580 (kernel 1020)

TCP:   8 (estab 2, closed 1, orphaned 0, synrecv 0, timewait 0/0), ports 0

Transport Total     IP        IPv6

*      1020      -         -

RAW      0         0         0

UDP      4         3         1

TCP      7         4         3

INET      11        7         4

FRAG      0         0         0

使用场景2：查看所有打开的网络端口[[email protected] ~]# ss -l

Netid State      Recv-Q Send-Q           Local Address:Port                            Peer Address:Port

nl    UNCONN     0      0                         rtnl:1736442360                                  *

nl    UNCONN     768    0                         rtnl:dockerd/853                                 *

nl    UNCONN     0      0                         rtnl:kernel                                      *

nl    UNCONN     0      0                         rtnl:1736442360                                  *

nl    UNCONN     4352   0                      tcpdiag:ss/4865                                     *

nl    UNCONN     768    0                      tcpdiag:kernel                                      *

nl    UNCONN     0      0                         xfrm:kernel                                      *

nl    UNCONN     0      0                         xfrm:dockerd/853                                 *

nl    UNCONN     0      0                      selinux:kernel                                      *

[[email protected] ~]# ss -pl  #列出具体的程序名字

Netid State      Recv-Q Send-Q           Local Address:Port                            Peer Address:Port

nl    UNCONN     0      0                         rtnl:1736442360                                  *

nl    UNCONN     768    0                         rtnl:dockerd/853                                 *

tcp LISTEN 0 128 :::http :::* users:(("httpd",pid=2493,fd=4),("httpd",pid=2492,fd=4),("httpd",pid=2491,fd=4),("httpd",pid=2490,fd=4),("httpd",pid=2489,fd=4),("httpd",pid=852,fd=4))

tcp   LISTEN     0      128                         :::ssh                                       :::*

使用场景3：查看这台服务器上所有的Socket 连接

[[email protected] ~]# ss -a   #列出所有网络连接

Netid State      Recv-Q Send-Q           Local Address:Port                            Peer Address:Port

nl    UNCONN     0      0                         rtnl:1736442360                                  *

nl    UNCONN     768    0                         rtnl:dockerd/853                                 *

nl    UNCONN     0      0                         rtnl:kernel                                      *

nl    UNCONN     0      0                         rtnl:1736442360                                  *

[[email protected] ~]# ss -ta   #查看TCP socket

State       Recv-Q Send-Q             Local Address:Port                              Peer Address:Port

LISTEN      0      128                            *:ssh                                          *:*

LISTEN      0      100                    127.0.0.1:smtp                                         *:*

ESTAB       0      0                 192.168.19.129:ssh                               192.168.19.1:ratio-adp

ESTAB       0      0                 192.168.19.129:ssh                               192.168.19.1:cpq-wbem

LISTEN      0      128                           :::http                                        :::*

LISTEN      0      128                           :::ssh                                         :::*

LISTEN      0      100                          ::1:smtp                                        :::*

[[email protected] ~]# ss -ua   #查看UDP  Socket

State       Recv-Q Send-Q             Local Address:Port                              Peer Address:Port

UNCONN      0      0                      127.0.0.1:323                                          *:*

ESTAB       0      0                 192.168.19.129:53193                            185.134.197.4:ntp

ESTAB       0      0                 192.168.19.129:55294                           193.228.143.12:ntp

ESTAB       0      0                 192.168.19.129:49316                           85.199.214.101:ntp

UNCONN      0      0                            ::1:323                                         :::*

[[email protected] ~]#

[[email protected] ~]# ss -wa   #查看RAW socket

State       Recv-Q Send-Q             Local Address:Port                              Peer Address:Port

[[email protected] ~]# ss -xa   #查看UNIX socket

Netid State      Recv-Q Send-Q           Local Address:Port                            Peer Address:Port

u_str LISTEN     0      128    /run/docker/libnetwork/2607d31c4b65ff68cf08c24cc6d5e4687dad654f9ec402872e98f8dcc79f448f.sock 25859                                      * 0

u_str LISTEN     0      100            private/rewrite 24960                                      * 0

u_str LISTEN     0      100             private/bounce 24963                                      * 0

u_str LISTEN     0      100              private/defer 24966                                      * 0

u_str LISTEN     0      100              private/trace 24969                                      * 0

三、netstat和ss之间替换命令

1、命令替换

2、软件包替换