每天一个linux命令(57):ss命令

ss是Socket Statistics​的缩写。顾名思义,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ss的优势在于它能够显示更多更详细的有关TCP和连接状态的信息,而且比netstat更快速更高效。
当服务器的socket连接数量变得非常大时,无论是使用netstat命令还是直接cat /proc/net/tcp,执行速度都会很慢。可能你不会有切身的感受,但请相信我,当服务器维持的连接达到上万个的时候,使用netstat等于浪费 生命,而用ss才是节省时间。
天下武功唯快不破。ss快的秘诀在于,它利用到了TCP协议栈中tcp_diag。tcp_diag是一个用于分析统计的模块,可以获得Linux 内核中第一手的信息,这就确保了ss的快捷高效。当然,如果你的系统中没有tcp_diag,ss也可以正常运行,只是效率会变得稍慢。(但仍然比 netstat要快。)
1.命令格式:
ss [参数]
ss [参数] [过滤]
2.命令功能:
ss(Socket Statistics的缩写)命令可以用来获取 socket统计信息,此命令输出的结果类似于 netstat输出的内容,但它能显示更多更详细的 TCP连接状态的信息,且比 netstat 更快速高效。它使用了 TCP协议栈中 tcp_diag(是一个用于分析统计的模块),能直接从获得第一手内核信息,这就使得 ss命令快捷高效。在没有 tcp_diag,ss也可以正常运行。
3.命令参数:
-h, --help 帮助信息
-V, --version #p#分页标题#e#程序版本信息
-n, --numeric 不解析服务名称
-r, --resolve        解析主机名
-a, --all 显示所有套接字(sockets)
-l, --listening 显示监听状态的套接字(sockets)
-o, --options        显示计时器信息
-e, --extended       显示详细的套接字(sockets)信息
-m, --memory         显示套接字(socket)的内存使用情况
-p, --processes 显示使用套接字(socket)的进程
-i, --info 显示 TCP内部信息
-s, --summary 显示套接字(socket)使用概况
-4, --ipv4           仅显示IPv4的套接字(sockets)
-6, --ipv6           仅显示IPv6的套接字(sockets)
#p#分页标题#e#-0, --packet         显示 PACKET 套接字(socket)
-t, --tcp 仅显示 TCP套接字(sockets)
-u, --udp 仅显示 UCP套接字(sockets)
-d, --dccp 仅显示 DCCP套接字(sockets)
-w, --raw 仅显示 RAW套接字(sockets)
-x, --unix 仅显示 Unix套接字(sockets)
-f, --family=FAMILY  显示 FAMILY类型的套接字(sockets),FAMILY可选,支持  unix, inet, inet6, link, netlink
-A, --query=QUERY, --socket=QUERY
      QUERY := {all|inet|tcp|udp|raw|unix|packet|netlink}[,QUERY]
-D, --diag=FILE     将原始TCP套接字(sockets)信息转储到文件
-F, --filter=FILE   从文件中都去过滤器信息
       FILTER := [ state TCP-STATE ] [ EXPRESSION ]

4.#p#分页标题#e#使用实例:
实例1:显示TCP连接
命令:
ss -t -a
输出:

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[root@localhost ~]# ss -t -a
State      Recv-Q Send-Q                                Local Address:Port                                    Peer Address:Port  
LISTEN     0      0                                         127.0.0.1:smux                                               *:*      
LISTEN     0      0                                                 *:3690                                               *:*      
LISTEN     0      0                                                 *:ssh                                                *:*       #p#分页标题#e#
ESTAB      0      0                                   192.168.120.204:ssh                                        10.2.0.68:49368  
[root@localhost ~]#
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说明:

实例2:显示 Sockets 摘要
命令:
ss -s
输出:

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[root@localhost ~]# ss -s
Total: 34 (kernel 48)
TCP:   4 (estab 1, closed 0, orphaned 0, synrecv 0, timewait 0/0), ports 3

Transport Total     IP        IPv6
*         48        -         -       
RAW       0         0         0        #p#分页标题#e#
UDP       5         5         0       
TCP       4         4         0       
INET      9         9         0       
FRAG      0         0         0       

[root@localhost ~]#
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说明:
列出当前的established, closed, orphaned and waiting TCP sockets

实例3:列出所有打开的网络连接端口
命令:
ss -l
输出:

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[root@localhost ~]# ss -l
Recv-Q Send-Q                                     Local Address:Port                                         Peer Address:Port   #p#分页标题#e#
0      0                                              127.0.0.1:smux                                                    *:*      
0      0                                                      *:3690                                                    *:*      
0      0                                                      *:ssh                                                     *:*      
[root@localhost ~]# 
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说明:

实例4:查看进程使用的socket
命令:
ss -pl
输出:
#p#分页标题#e#

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[root@localhost ~]# ss -pl
Recv-Q Send-Q                                     Local Address:Port                                         Peer Address:Port  
0      0                                              127.0.0.1:smux                                                    *:*        users:(("snmpd",2716,8))
0      0                                                      *:3690                                                    *:*        users:(("svnserve",3590,3))
0      0                                                      *:ssh                                                     *:*        users:((#p#分页标题#e#"sshd",2735,3))
[root@localhost ~]#
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说明:

实例5:找出打开套接字/端口应用程序
命令:
ss -lp | grep 3306
输出:

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[root@localhost ~]# ss -lp|grep 1935
0      0                            *:1935                          *:*        users:(("fmsedge",2913,18))
0      0                    127.0.0.1:19350                         *:*        users:((#p#分页标题#e#"fmsedge",2913,17))
[root@localhost ~]# ss -lp|grep 3306
0      0                            *:3306                          *:*        users:(("mysqld",2871,10))
[root@localhost ~]#
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说明:

实例6:显示所有UDP Sockets
命令:
ss -u -a
输出:

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[root@localhost ~]# ss -u -a
State      Recv-Q Send-Q                                Local Address:Port                                    Peer Address:Port   #p#分页标题#e#
UNCONN     0      0                                         127.0.0.1:syslog                                             *:*      
UNCONN     0      0                                                 *:snmp                                               *:*      
ESTAB      0      0                                   192.168.120.203:39641                                  10.58.119.119:domain
[root@localhost ~]#
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说明:

实例7:显示所有状态为established的SMTP连接
命令:
ss -o state established '( dport = :smtp or sport = :smtp )'
输出:

[root@localhost ~]#p#分页标题#e## ss -o state established '( dport = :smtp or sport = :smtp )'
Recv-Q Send-Q                                     Local Address:Port                                         Peer Address:Port  
[root@localhost ~]#
说明:

实例8:显示所有状态为Established的HTTP连接
命令:
ss -o state established '( dport = :http or sport = :http )'
输出:

[root@localhost ~]# ss -o state established '( dport = :http or sport = :http )'
Recv-Q Send-Q                                     Local Address:Port                                         Peer Address:Port  
0      0                                              75.126.153.214:2164                                        192.168.10.42:http    #p#分页标题#e#
[root@localhost ~]#
说明:

实例9:列举出处于 FIN-WAIT-1状态的源端口为 80或者 443,目标网络为 193.233.7/24所有 tcp套接字
命令:
ss -o state fin-wait-1 '( sport = :http or sport = :https )' dst 193.233.7/24
输出:
说明:

实例10:用TCP 状态过滤Sockets:
命令:
ss -4 state FILTER-NAME-HERE
ss -6 state FILTER-NAME-HERE
输出:
[root@localhost ~]#ss -4 state closing
Recv-Q Send-Q                                                  Local Address:Port                                                      Peer Address:Port #p#分页标题#e#
1      11094                                                  75.126.153.214:http                                                      192.168.10.42:4669

说明:
FILTER-NAME-HERE 可以代表以下任何一个:
established
syn-sent
syn-recv
fin-wait-1
fin-wait-2
time-wait
closed
close-wait
last-ack
listen
closing

all : 所有以上状态
connected : 除了listen and closed的所有状态
synchronized :所有已连接的状态除了syn-sent
bucket : 显示状态为maintained as minisockets,如:time-wait和syn-recv.#p#分页标题#e#
big : 和bucket相反.

实例11:匹配远程地址和端口号
命令:
ss dst ADDRESS_PATTERN
ss dst 192.168.1.5
ss dst 192.168.119.113:http
ss dst 192.168.119.113:smtp
ss dst 192.168.119.113:443
输出:

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[root@localhost ~]# ss dst 192.168.119.113
State      Recv-Q Send-Q                                Local Address:Port                                    Peer Address:Port  
ESTAB      0      0                                   192.168.119.103:16014                                192.168.119.113:20229  
ESTAB      0      0                                   192.168.119.103:16014                                192.168.119.113:61056   #p#分页标题#e#
ESTAB      0      0                                   192.168.119.103:16014                                192.168.119.113:61623  
ESTAB      0      0                                   192.168.119.103:16014                                192.168.119.113:60924  
ESTAB      0      0                                   192.168.119.103:16050                                192.168.119.113:43701  
ESTAB      0      0                                   192.168.119.103:16073                                192.168.119.113:32930  
ESTAB      0      0                                   192.168.119.103:16073                                192.168.119.113:49318  
ESTAB      0      0                                   192.168.119.103:16014                                192.168.119.113:3844   
[root@localhost ~]# ss dst 192.168.119.113:http
State      Recv-Q Send-Q                                Local Address:Port                                    Peer Address:Port   #p#分页标题#e#
[root@localhost ~]# ss dst 192.168.119.113:3844
State      Recv-Q Send-Q                                Local Address:Port                                    Peer Address:Port  
ESTAB      0      0                                   192.168.119.103:16014                                192.168.119.113:3844   
[root@localhost ~]#
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说明:

实例12:匹配本地地址和端口号
命令:
ss src ADDRESS_PATTERN
ss src 192.168.119.103
ss src 192.168.119.103:http
ss src 192.168.119.103:80
ss src 192.168.119.103:smtp
ss src 192.168.119.103:25
输出:#p#分页标题#e#

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[root@localhost ~]# ss src 192.168.119.103:16021
State      Recv-Q Send-Q                                Local Address:Port                                    Peer Address:Port  
ESTAB      0      0                                   192.168.119.103:16021                                192.168.119.201:63054  
ESTAB      0      0                                   192.168.119.103:16021                                192.168.119.201:62894  
ESTAB      0      0                                   192.168.119.103:16021                                192.168.119.201:63055  
ESTAB      0      0                                   192.168.119.103:16021                                192.168.119.201:2274   
ESTAB      0      0                                   192.168.119.103:16021                                192.168.119.201:44784   #p#分页标题#e#
ESTAB      0      0                                   192.168.119.103:16021                                192.168.119.201:7233   
ESTAB      0      0                                   192.168.119.103:16021                                192.168.119.103:58660  
ESTAB      0      0                                   192.168.119.103:16021                                192.168.119.201:44822  
ESTAB      0      0                                   192.168.119.103:16021                                     10.2.1.206:56737  
ESTAB      0      0                                   192.168.119.103:16021                                     10.2.1.206:57487  
ESTAB      0      0                                   192.168.119.103:16021                                     10.2.1.206:56736  
ESTAB      0      0                                   192.168.119.103:16021                                     10.2.1.206:64652   #p#分页标题#e#
ESTAB      0      0                                   192.168.119.103:16021                                     10.2.1.206:56586  
ESTAB      0      0                                   192.168.119.103:16021                                     10.2.1.206:64653  
ESTAB      0      0                                   192.168.119.103:16021                                     10.2.1.206:56587  
[root@localhost ~]#
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说明:

实例13:将本地或者远程端口和一个数比较
命令:
ss dport OP PORT
ss sport OP PORT
输出:
#p#分页标题#e#
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[root@localhost ~]# ss  sport = :http
[root@localhost ~]# ss  dport = :http
[root@localhost ~]# ss  dport \> :1024
[root@localhost ~]# ss  sport \> :1024
[root@localhost ~]# ss sport \< :32000
[root@localhost ~]# ss  sport eq :22
[root@localhost ~]# ss  dport != :22
[root@localhost ~]# ss  state connected sport = :http
[root@localhost ~]# ss \( sport = :http or sport = :https \)
[root@localhost ~]# ss -o state fin-wait-1 \( sport = :http or sport = :https \) dst 192.168.1/24
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说明:#p#分页标题#e#
ss dport OP PORT 远程端口和一个数比较;ss sport OP PORT 本地端口和一个数比较。
OP 可以代表以下任意一个:
<= or le : 小于或等于端口号
>= or ge : 大于或等于端口号
== or eq : 等于端口号
!= or ne : 不等于端口号
< or gt : 小于端口号
> or lt : 大于端口号

实例14:ss 和 netstat 效率对比
命令:
time netstat -at
time ss
输出:

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[root@localhost ~]# time ss   #p#分页标题#e#
real    0m0.739s
user    0m0.019s
sys     0m0.013s
[root@localhost ~]#
[root@localhost ~]# time netstat -at
real    2m45.907s
user    0m0.063s
sys     0m0.067s
[root@localhost ~]#
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说明:
用time 命令分别获取通过netstat和ss命令获取程序和概要占用资源所使用的时间。在服务器连接数比较多的时候,netstat的效率完全没法和ss比。

转载于:http://www.itxuexiwang.com/a/liunxjishu/2016/0303/210.html?1457084072

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转载自zhaomengsen.iteye.com/blog/2280669