二十五岁时我们都一样愚蠢、多愁善感，喜欢故弄玄虚，可如果不那样的话，五十岁时也就不会如此明智。
标题：Linux shell netstat 命令
Linux shell netstat 命令用于显示网络状态。
利用 netstat 指令可让你得知整个 Linux 系统的网络情况。
netstat 命令语法格式
netstat [-acCeFghilMnNoprstuvVwx][-A<网络类型>][--ip]选项
- -a , --all
- 显示所有连线中的Socket。
- -A<网络类型> , --<网络类型>
- 列出该网络类型连线中的相关地址。
- -c , --continuous
- 持续列出网络状态。
- -C , --cache
- 显示路由器配置的快取信息。
- -e , --extend
- 显示网络其他相关信息。
- -F , --fib
- 显示FIB。
- -g , --groups
- 显示多重广播功能群组组员名单。
- -h , --help
- 在线帮助。
- -i , --interfaces
- 显示网络界面信息表单。
- -l , --listening
- 显示监控中的服务器的Socket。
- -M , --masquerade
- 显示伪装的网络连线。
- -n , --numeric
- 直接使用IP地址，而不通过域名服务器。
- -N , --netlink , --symbolic
- 显示网络硬件外围设备的符号连接名称。
- -o , --timers
- 显示计时器。
- -p , --programs
- 显示正在使用Socket的程序识别码和程序名称。
- -r , --route
- 显示Routing Table。
- -s , --statistice
- 显示网络工作信息统计表。
- -t , --tcp
- 显示TCP传输协议的连线状况。
- -u , --udp
- 显示UDP传输协议的连线状况。
- -v , --verbose
- 显示指令执行过程。
- -V , --version
- 显示版本信息。
- -w , --raw
- 显示RAW传输协议的连线状况。
- -x , --unix
- 此参数的效果和指定"-A unix"参数相同。
- --ip , --inet
- 此参数的效果和指定"-A inet"参数相同。
范例
范例 1 ： 显示详细的网络状况
[root@localhost ~]# netstat -a Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 0.0.0.0:ssh 0.0.0.0:* LISTEN tcp 0 0 localhost:smtp 0.0.0.0:* LISTEN tcp 0 0 localhost.localdoma:ssh 192.168.0.100:64504 ESTABLISHED tcp6 0 0 [::]:ssh [::]:* LISTEN tcp6 0 0 [::]:telnet [::]:* LISTEN tcp6 0 0 localhost:smtp [::]:* LISTEN udp 0 0 0.0.0.0:bootpc 0.0.0.0:* udp 0 0 0.0.0.0:23698 0.0.0.0:* udp6 0 0 [::]:62067 [::]:* Active UNIX domain sockets (servers and established) Proto RefCnt Flags Type State I-Node Path unix 2 [ ] DGRAM 8466 /run/systemd/notify ....范例 2 ： 显示当前用户 UDP 连接状况
[root@localhost ~]# netstat -nu Active Internet connections (w/o servers) Proto Recv-Q Send-Q Local Address Foreign Address State [root@localhost ~]#范例 3 ： 显示UDP端口号的使用情况
[root@localhost ~]# netstat -apu Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name udp 0 0 0.0.0.0:bootpc 0.0.0.0:* 792/dhclient udp 0 0 0.0.0.0:23698 0.0.0.0:* 792/dhclient udp6 0 0 [::]:62067 [::]:* 792/dhclient [root@localhost ~]#范例 4 ： 显示网卡列表
[root@localhost ~]# netstat -i Kernel Interface table Iface MTU RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg ens33 1500 147 0 0 0 94 0 0 0 BMRU lo 65536 0 0 0 0 0 0 0 0 LRU [root@localhost ~]#范例 4 ： 显示组播组的关系
[root@localhost ~]# netstat -g IPv6/IPv4 Group Memberships Interface RefCnt Group --------------- ------ --------------------- lo 1 all-systems.mcast.net ens33 1 all-systems.mcast.net lo 1 ff02::1 lo 1 ff01::1 ens33 1 ff02::1:ff0c:6d90 ens33 1 ff02::1 ens33 1 ff01::1 [root@localhost ~]#范例 5 ： 显示网络统计信息
[root@localhost ~]# netstat -s Ip: 169 total packets received 0 forwarded 0 incoming packets discarded 157 incoming packets delivered 91 requests sent out Icmp: 19 ICMP messages received 1 input ICMP message failed. ICMP input histogram: redirects: 19 0 ICMP messages sent 0 ICMP messages failed ICMP output histogram: IcmpMsg: InType5: 19 Tcp: 0 active connections openings 1 passive connection openings 0 failed connection attempts 0 connection resets received 1 connections established 126 segments received 83 segments send out 1 segments retransmited 0 bad segments received. 1 resets sent Udp: 12 packets received 0 packets to unknown port received. 0 packet receive errors 12 packets sent 0 receive buffer errors 0 send buffer errors UdpLite: TcpExt: 13 ICMP packets dropped because socket was locked 3 delayed acks sent 1 packet headers predicted 68 acknowledgments not containing data payload received 6 predicted acknowledgments TCPLossProbes: 1 1 DSACKs received IPReversePathFilter: 2 TCPOrigDataSent: 73 TCPHystartTrainDetect: 1 TCPHystartTrainCwnd: 17 IpExt: InBcastPkts: 10 InOctets: 16918 OutOctets: 22030 InBcastOctets: 1450 InNoECTPkts: 169 [root@localhost ~]#范例 6 ： 显示监听的套接口
[root@localhost ~]# netstat -l Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 0.0.0.0:ssh 0.0.0.0:* LISTEN tcp 0 0 localhost:smtp 0.0.0.0:* LISTEN tcp6 0 0 [::]:ssh [::]:* LISTEN tcp6 0 0 [::]:telnet [::]:* LISTEN tcp6 0 0 localhost:smtp [::]:* LISTEN udp 0 0 0.0.0.0:bootpc 0.0.0.0:* udp 0 0 0.0.0.0:23698 0.0.0.0:* udp6 0 0 [::]:62067 [::]:* Active UNIX domain sockets (only servers) Proto RefCnt Flags Type State I-Node Path unix 2 [ ACC ] STREAM LISTENING 8482 /run/systemd/journal/stdout unix 2 [ ACC ] STREAM LISTENING 18228 /var/run/NetworkManager/private-dhcp unix 2 [ ACC ] STREAM LISTENING 15685 /var/run/dbus/system_bus_socket unix 2 [ ACC ] STREAM LISTENING 12918 /run/systemd/private unix 2 [ ACC ] STREAM LISTENING 16524 /var/run/vmware/guestServicePipe unix 2 [ ACC ] STREAM LISTENING 12941 /run/lvm/lvmpolld.socket unix 2 [ ACC ] STREAM LISTENING 12952 /run/lvm/lvmetad.socket unix 2 [ ACC ] STREAM LISTENING 19673 private/verify unix 2 [ ACC ] STREAM LISTENING 19679 private/proxymap unix 2 [ ACC ] STREAM LISTENING 19682 private/proxywrite unix 2 [ ACC ] STREAM LISTENING 19685 private/smtp unix 2 [ ACC ] STREAM LISTENING 19688 private/relay unix 2 [ ACC ] STREAM LISTENING 19694 private/error unix 2 [ ACC ] STREAM LISTENING 19697 private/retry unix 2 [ ACC ] STREAM LISTENING 19700 private/discard unix 2 [ ACC ] STREAM LISTENING 19703 private/local unix 2 [ ACC ] STREAM LISTENING 19706 private/virtual unix 2 [ ACC ] STREAM LISTENING 19709 private/lmtp unix 2 [ ACC ] STREAM LISTENING 19712 private/anvil unix 2 [ ACC ] STREAM LISTENING 19715 private/scache unix 2 [ ACC ] STREAM LISTENING 19658 private/tlsmgr unix 2 [ ACC ] STREAM LISTENING 19670 private/trace unix 2 [ ACC ] STREAM LISTENING 19661 private/rewrite unix 2 [ ACC ] STREAM LISTENING 19647 public/pickup unix 2 [ ACC ] STREAM LISTENING 19664 private/bounce unix 2 [ ACC ] STREAM LISTENING 19651 public/cleanup unix 2 [ ACC ] STREAM LISTENING 19654 public/qmgr unix 2 [ ACC ] STREAM LISTENING 19676 public/flush unix 2 [ ACC ] STREAM LISTENING 19667 private/defer unix 2 [ ACC ] STREAM LISTENING 19691 public/showq unix 2 [ ACC ] SEQPACKET LISTENING 13026 /run/udev/control
