ss命令用于显示socket状态. 他可以显示PACKET sockets, TCP sockets, UDP sockets, DCCP sockets, RAW sockets, Unix domain sockets等等统计. 它比其他工具展示等多tcp和state信息. 它是一个非常实用、快速、有效的跟踪IP连接和sockets的新工具.SS命令可以提供如下信息：
- 所有的TCP sockets
- 所有的UDP sockets
- 所有ssh/ftp/ttp/https持久连接
- 所有连接到Xserver的本地进程
- 使用state（例如：connected, synchronized, SYN-RECV, SYN-SENT,TIME-WAIT）、地址、端口过滤
- 所有的state FIN-WAIT-1 tcpsocket连接以及更多
很多流行的Linux发行版都支持ss以及很多监控工具使用ss命令.熟悉这个工具有助于您更好的发现与解决系统性能问题.本人强烈建议使用ss命令替代netstat部分命令,例如netsat -ant/lnt等.
展示他之前来做个对比,统计服务器并发连接数
1 2 3 4 5 6 7 8 9 10 11 12 13 | netstat # time netstat -ant | grep EST | wc -l 3100 real 0m12.960s user 0m0.334s sys 0m12.561s # time ss -o state established | wc -l 3204 real 0m0.030s user 0m0.005s sys 0m0.026s |
结果很明显ss统计并发连接数效率完败netstat,在ss能搞定的情况下, 你还会在选择netstat吗, 还在犹豫吗, 看以下例子,或者跳转到帮助页面.
常用ss命令：
1 2 3 4 5 6 7 8 | ss –l 显示本地打开的所有端口 ss –pl 显示每个进程具体打开的socket ss –t –a 显示所有tcp socket ss –u –a 显示所有的UDP Socekt ss –o state established ‘( dport = :smtp or sport = :smtp )’ 显示所有已建立的SMTP连接 ss –o state established ‘( dport = :http or sport = :http )’ 显示所有已建立的HTTP连接 ss –x src /tmp/.X11–unix/* 找出所有连接X服务器的进程 ss –s 列出当前socket详细信息: |
显示sockets简要信息
列出当前已经连接，关闭，等待的tcp连接
1 2 3 4 5 6 7 8 9 10 11 | # ss -s Total: 3519 (kernel 3691) TCP: 26557 (estab 3163, closed 23182, orphaned 194, synrecv 0, timewait 23182/0), ports 1452 Transport Total IP IPv6 * 3691 – – RAW 2 2 0 UDP 10 7 3 TCP 3375 3368 7 INET 3387 3377 10 FRAG 0 0 0 |
列出当前监听端口
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | # ss -l Recv–Q Send–Q Local Address:Port Peer Address:Port 0 10 :::5989 :::* 0 5 *:rsync *:* 0 128 :::sunrpc :::* 0 128 *:sunrpc *:* 0 511 *:http *:* 0 128 :::ssh :::* 0 128 *:ssh *:* 0 128 :::35766 :::* 0 128 127.0.0.1:ipp *:* 0 128 ::1:ipp :::* 0 100 ::1:smtp :::* 0 100 127.0.0.1:smtp *:* 0 511 *:https *:* 0 100 :::1311 :::* 0 5 *:5666 *:* 0 128 *:3044 *:* |
ss列出每个进程名及其监听的端口
1 | # ss -pl |
ss列所有的tcp sockets
1 | # ss -t -a |
ss列出所有udp sockets
1 | # ss -u -a |
ss列出所有http连接中的连接
1 | # ss -o state established ‘( dport = :http or sport = :http )’ |
·以上包含对外提供的80，以及访问外部的80
·用以上命令完美的替代netstat获取http并发连接数，监控中常用到
ss列出本地哪个进程连接到x server
1 | # ss -x src /tmp/.X11-unix/* |
ss列出处在FIN-WAIT-1状态的http、https连接
1 | # ss -o state fin-wait-1 ‘( sport = :http or sport = :https )’ |
ss常用的state状态：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | established syn–sent syn–recv fin–wait–1 fin–wait–2 time–wait closed close–wait last–ack listen closing all : All of the above states connected : All the states except for listen and closed synchronized : All the connected states except for syn–sent bucket : Show states, which are maintained as minisockets, i.e. time–wait and syn–recv. big : Opposite to bucket state. |
ss使用IP地址筛选
1 2 3 4 5 6 7 8 9 10 | ss src ADDRESS_PATTERN src：表示来源 ADDRESS_PATTERN：表示地址规则 如下： ss src 120.33.31.1 # 列出来之20.33.31.1的连接 ＃ 列出来至120.33.31.1,80端口的连接 ss src 120.33.31.1:http ss src 120.33.31.1:80 |
ss使用端口筛选
1 2 3 4 | ss dport OP PORT OP:是运算符 PORT：表示端口 dport：表示过滤目标端口、相反的有sport |
OP运算符如下：
1 2 3 4 | <= or le : 小于等于 >= or ge : 大于等于 == or eq : 等于 != or ne : 不等于端口 < or lt : 小于这个端口 > or gt : 大于端口 |
OP实例
1 2 3 4 5 6 7 8 9 10 | ss sport = :http 也可以是 ss sport = :80 ss dport = :http ss dport \> :1024 ss sport \> :1024 ss sport \< :32000 ss sport eq :22 ss dport != :22 ss state connected sport = :http ss \( sport = :http or sport = :https \) ss –o state fin–wait–1 \( sport = :http or sport = :https \) dst 192.168.1/24 |
为什么ss比netstat快：
netstat是遍历/proc下面每个PID目录，ss直接读/proc/net下面的统计信息。所以ss执行的时候消耗资源以及消耗的时间都比netstat少很多
ss命令帮助
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 | # ss -h Usage: ss [ OPTIONS ] ss [ OPTIONS ] [ FILTER ] –h, —help this message –V, —version output version information –n, —numeric don‘t resolve service names –r, —resolve resolve host names –a, —all display all sockets –l, —listening display listening sockets –o, —options show timer information –e, —extended show detailed socket information –m, —memory show socket memory usage –p, —processes show process using socket –i, —info show internal TCP information –s, —summary show socket usage summary –4, —ipv4 display only IP version 4 sockets –6, —ipv6 display only IP version 6 sockets –0, —packet display PACKET sockets –t, —tcp display only TCP sockets –u, —udp display only UDP sockets –d, —dccp display only DCCP sockets –w, —raw display only RAW sockets –x, —unix display only Unix domain sockets –f, —family=FAMILY display sockets of type FAMILY –A, —query=QUERY, —socket=QUERY QUERY := {all|inet|tcp|udp|raw|unix|packet|netlink}[,QUERY] –D, —diag=FILE Dump raw information about TCP sockets to FILE –F, —filter=FILE read filter information from FILE FILTER := [ state TCP–STATE ] [ EXPRESSION ] |
参考：http://www.cyberciti.biz/tips/linux-investigate-sockets-network-connections.html
