linux下网络故障常用的几个命令
ifconfig
ubuntu@VM-0-3-ubuntu:~$ ifconfig docker0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500 inet 172.17.0.1 netmask 255.255.0.0 broadcast 172.17.255.255 ether 02:42:49:13:91:23 txqueuelen 0 (Ethernet) RX packets 0 bytes 0 (0.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 0 bytes 0 (0.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 172.16.0.3 netmask 255.255.240.0 broadcast 172.16.15.255 inet6 fe80::5054:ff:fe9b:8405 prefixlen 64 scopeid 0x20<link> ether 52:54:00:9b:84:05 txqueuelen 1000 (Ethernet) RX packets 48359052 bytes 4512423724 (4.5 GB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 47191232 bytes 4195297257 (4.1 GB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10<host> loop txqueuelen 1000 (Local Loopback) RX packets 1352984 bytes 110930762 (110.9 MB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 1352984 bytes 110930762 (110.9 MB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
可以方便的查看本机的几个网卡
ping
ubuntu@VM-0-3-ubuntu:~$ ping www.baidu.com PING www.a.shifen.com (14.215.177.39) 56(84) bytes of data. 64 bytes from 14.215.177.39 (14.215.177.39): icmp_seq=1 ttl=54 time=2.88 ms 64 bytes from 14.215.177.39 (14.215.177.39): icmp_seq=2 ttl=54 time=2.79 ms 64 bytes from 14.215.177.39 (14.215.177.39): icmp_seq=3 ttl=54 time=2.78 ms 64 bytes from 14.215.177.39 (14.215.177.39): icmp_seq=4 ttl=54 time=2.84 ms 64 bytes from 14.215.177.39 (14.215.177.39): icmp_seq=5 ttl=54 time=2.90 ms ^C --- www.a.shifen.com ping statistics --- 5 packets transmitted, 5 received, 0% packet loss, time 4006ms rtt min/avg/max/mdev = 2.781/2.837/2.898/0.047 ms
可以查看目标机器是否ping通
telnet
ubuntu@VM-0-3-ubuntu:~$ telnet 127.0.0.1 3000 Trying 127.0.0.1... Connected to 127.0.0.1. Escape character is '^]'. sfsdf
netstat
ubuntu@VM-0-3-ubuntu:~$ netstat -atn Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN tcp 0 0 172.17.0.1:53 0.0.0.0:* LISTEN tcp 0 0 172.16.0.3:53 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:53 0.0.0.0:* LISTEN tcp 0 0 127.0.0.53:53 0.0.0.0:* LISTEN tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN tcp 0 0 0.0.0.0:3000 0.0.0.0:* LISTEN tcp 0 0 0.0.0.0:3000 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:953 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:6010 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:6011 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:6012 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:6013 0.0.0.0:* LISTEN tcp 0 0 172.16.0.3:111 206.81.10.86:58812 ESTABLISHED tcp 0 0 172.16.0.3:22 183.198.11.196:21580 ESTABLISHED tcp 0 0 127.0.0.1:3000 127.0.0.1:58318 TIME_WAIT tcp 0 0 172.16.0.3:22 183.198.11.196:21602 ESTABLISHED tcp 0 0 172.16.0.3:22 183.198.11.196:22039 ESTABLISHED tcp 0 0 172.16.0.3:39816 169.254.0.55:5574 ESTABLISHED tcp 0 0 172.16.0.3:111 192.3.116.182:46844 ESTABLISHED tcp 0 0 172.16.0.3:22 183.198.11.196:22025 ESTABLISHED tcp 0 0 172.16.0.3:111 170.130.187.34:51001 ESTABLISHED tcp 0 0 172.16.0.3:22 183.198.11.196:22506 ESTABLISHED tcp 0 0 172.16.0.3:50948 169.254.0.138:8086 ESTABLISHED tcp 0 0 172.16.0.3:22 183.198.11.196:22495 ESTABLISHED tcp 0 0 172.16.0.3:111 164.90.208.105:46554 ESTABLISHED tcp 0 0 172.16.0.3:22 183.198.11.196:22453 ESTABLISHED tcp 0 3360 172.16.0.3:22 183.198.11.196:22438 ESTABLISHED tcp6 0 0 :::111 :::* LISTEN tcp6 0 0 ::1:53 :::* LISTEN
ubuntu@VM-0-3-ubuntu:~$ netstat -aun Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State udp 0 0 172.17.0.1:53 0.0.0.0:* udp 0 0 172.16.0.3:53 0.0.0.0:* udp 0 0 127.0.0.1:53 0.0.0.0:* udp 0 0 127.0.0.53:53 0.0.0.0:* udp 0 0 172.16.0.3:68 0.0.0.0:* udp 0 0 0.0.0.0:111 0.0.0.0:* udp 0 0 127.0.0.1:123 0.0.0.0:* udp 0 0 172.16.0.3:123 0.0.0.0:* udp6 0 0 fe80::5054:ff:fe9b:8:53 :::* udp6 0 0 ::1:53 :::* udp6 0 0 :::111 :::* udp6 0 0 ::1:123 :::* udp6 0 0 fe80::5054:ff:fe9b::123 :::*
lsof
root@VM-0-3-ubuntu:/home/ubuntu# lsof -i -Pn | grep "3000" epoll_ser 637850 root 3u IPv4 48974473 0t0 TCP *:3000 (LISTEN) epoll_ser 640784 root 3u IPv4 48991331 0t0 TCP *:3000 (LISTEN)
nc
ubuntu@VM-0-3-ubuntu:~$ nc -v 127.0.0.1 3000 # tcp 连接上去 Connection to 127.0.0.1 3000 port [tcp/*] succeeded! root@VM-0-3-ubuntu:/home/ubuntu/mybooksources-master/Chapter04/code# nc -v -l 127.0.0.1 3001 # 监听一个端口 Listening on localhost 3001 Connection received on localhost 39630 root@VM-0-3-ubuntu:/home/ubuntu/mybooksources-master/Chapter04/code# nc -v -l -u 127.0.0.1 3001 # 监听一个udp端口 Bound on localhost 3001 Connection received on localhost 50632 XXXXXdfdf sdfsdf ubuntu@VM-0-3-ubuntu:~$ nc -v -u 127.0.0.1 3001 # 连接udp dfdf Connection to 127.0.0.1 3001 port [udp/*] succeeded! sdfsdf
curl
ubuntu@VM-0-3-ubuntu:~$ curl www.baidu.com
<!DOCTYPE html>
<!--STATUS OK--><html> <head><meta http-equiv=content-type content=text/html;charset=utf-8><meta http-equiv=X-UA-Compatible content=IE=Edge><meta content=always name=referrer><link rel=stylesheet type=text/css href=http://s1.bdstatic.com/r/www/cache/bdorz/baidu.min.css><title>百度一下，你就知道</title></head> <body link=#0000cc> <div id=wrapper> <div id=head> <div class=head_wrapper> <div class=s_form> <div class=s_form_wrapper> <div id=lg> <img hidefocus=true src=//www.baidu.com/img/bd_logo1.png width=270 height=129> </div> <form id=form name=f action=//www.baidu.com/s class=fm> <input type=hidden name=bdorz_come value=1> <input type=hidden name=ie value=utf-8> <input type=hidden name=f value=8> <input type=hidden name=rsv_bp value=1> <input type=hidden name=rsv_idx value=1> <input type=hidden name=tn value=baidu><span class="bg s_ipt_wr"><input id=kw name=wd class=s_ipt value maxlength=255 autocomplete=off autofocus></span><span class="bg s_btn_wr"><input type=submit id=su value=百度一下 class="bg s_btn"></span> </form> </div> </div> <div id=u1> <a href=http://news.baidu.com name=tj_trnews class=mnav>新闻</a> <a href=http://www.hao123.com name=tj_trhao123 class=mnav>hao123</a> <a href=http://map.baidu.com name=tj_trmap class=mnav>地图</a> <a href=http://v.baidu.com name=tj_trvideo class=mnav>视频</a> <a href=http://tieba.baidu.com name=tj_trtieba class=mnav>贴吧</a> <noscript> <a href=http://www.baidu.com/bdorz/login.gif?login&tpl=mn&u=http%3A%2F%2Fwww.baidu.com%2f%3fbdorz_come%3d1 name=tj_login class=lb>登录</a> </noscript> <script>document.write('<a href="http://www.baidu.com/bdorz/login.gif?login&tpl=mn&u='+ encodeURIComponent(window.location.href+ (window.location.search === "" ? "?" : "&")+ "bdorz_come=1")+ '" name="tj_login" class="lb">登录</a>');</script> <a href=//www.baidu.com/more/ name=tj_briicon class=bri style="display: block;">更多产品</a> </div> </div> </div> <div id=ftCon> <div id=ftConw> <p id=lh> <a href=http://home.baidu.com>关于百度</a> <a href=http://ir.baidu.com>About Baidu</a> </p> <p id=cp>©2017 Baidu <a href=http://www.baidu.com/duty/>使用百度前必读</a> <a href=http://jianyi.baidu.com/ class=cp-feedback>意见反馈</a> 京ICP证030173号 <img src=//www.baidu.com/img/gs.gif> </p> </div> </div> </div> </body> </html>
tcpdump
root@VM-0-3-ubuntu:/home/ubuntu# tcpdump -i any "tcp port 3001" tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on any, link-type LINUX_SLL (Linux cooked v1), capture size 262144 bytes 19:56:12.928329 IP localhost.39946 > localhost.3001: Flags [S], seq 2726208034, win 65495, options [mss 65495,sackOK,TS val 2359419880 ecr 0,nop,wscale 7], length 0 19:56:12.928341 IP localhost.3001 > localhost.39946: Flags [S.], seq 3476933863, ack 2726208035, win 65483, options [mss 65495,sackOK,TS val 2359419880 ecr 2359419880,nop,wscale 7], length 0 19:56:12.928350 IP localhost.39946 > localhost.3001: Flags [.], ack 1, win 512, options [nop,nop,TS val 2359419880 ecr 2359419880], length 0 # 以上是抓包三次握手
