Linux netstat命令
Linux netstat命令
非常重要的命令，尤其是面对openresty、nginx等代理服务器，解决网络阻塞的关键命令
root@jdit:~# netstat -a | awk '/^tcp/ {++S[$NF]} END {for(a in S) print a, S[a]}'
LISTEN 5
ESTABLISHED 3
TIME_WAIT 1
Linux 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。
语法
netstat [-acCeFghilMnNoprstuvVwx][-A<网络类型>][--ip]
参数说明：
- -a或--all 显示所有连线中的Socket。
- -A<网络类型>或--<网络类型> 列出该网络类型连线中的相关地址。
- -c或--continuous 持续列出网络状态。
- -C或--cache 显示路由器配置的快取信息。
- -e或--extend 显示网络其他相关信息。
- -F或--fib 显示路由缓存。
- -g或--groups 显示多重广播功能群组组员名单。
- -h或--help 在线帮助。
- -i或--interfaces 显示网络界面信息表单。
- -l或--listening 显示监控中的服务器的Socket。
- -M或--masquerade 显示伪装的网络连线。
- -n或--numeric 直接使用IP地址，而不通过域名服务器。
- -N或--netlink或--symbolic 显示网络硬件外围设备的符号连接名称。
- -o或--timers 显示计时器。
- -p或--programs 显示正在使用Socket的程序识别码和程序名称。
- -r或--route 显示Routing Table。
- -s或--statistics 显示网络工作信息统计表。
- -t或--tcp 显示TCP传输协议的连线状况。
- -u或--udp 显示UDP传输协议的连线状况。
- -v或--verbose 显示指令执行过程。
- -V或--version 显示版本信息。
- -w或--raw 显示RAW传输协议的连线状况。
- -x或--unix 此参数的效果和指定"-A unix"参数相同。
- --ip或--inet 此参数的效果和指定"-A inet"参数相同。
实例
显示详细的网络状况
# netstat -a
显示当前户籍UDP连接状况
# netstat -nu
显示UDP端口号的使用情况
root@jdit:~# netstat -apu
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
udp 0 0 localhost:domain 0.0.0.0:* 71701/systemd-resol
udp 0 0 iZ2ze1w1u469cd5g:bootpc 0.0.0.0:* 4828/systemd-networ
udp 0 0 localhost:323 0.0.0.0:* 71734/chronyd
udp6 0 0 ip6-localhost:323 [::]:* 71734/chronyd
显示网卡列表
root@jdit:~# netstat -i
Kernel Interface table
Iface MTU RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg
eth0 1500 1526526 0 0 0 1190444 0 0 0 BMRU
lo 65536 183355 0 0 0 183355 0 0 0 LRU
显示组播组的关系
root@jdit:~# netstat -g
IPv6/IPv4 Group Memberships
Interface RefCnt Group
--------------- ------ ---------------------
lo 1 all-systems.mcast.net
eth0 1 all-systems.mcast.net
lo 1 ip6-allnodes
lo 1 ff01::1
eth0 1 ff02::1:ff12:126f
eth0 2 ip6-allnodes
eth0 1 ff01::1
root@jdit:~#
显示网络统计信息
root@jdit:~# netstat -s
Ip:
Forwarding: 2
1014665 total packets received
9 with invalid addresses
0 forwarded
0 incoming packets discarded
1014656 incoming packets delivered
975856 requests sent out
Icmp:
59888 ICMP messages received
40 input ICMP message failed
InCsumErrors: 13
ICMP input histogram:
destination unreachable: 133
echo requests: 59738
echo replies: 2
timestamp request: 2
59829 ICMP messages sent
0 ICMP messages failed
ICMP output histogram:
destination unreachable: 89
echo replies: 59738
timestamp replies: 2
IcmpMsg:
InType0: 2
InType3: 133
InType8: 59738
InType13: 2
OutType0: 59738
OutType3: 89
OutType14: 2
Tcp:
43576 active connection openings
1348 passive connection openings
23788 failed connection attempts
425 connection resets received
3 connections established
696441 segments received
683395 segments sent out
2873 segments retransmitted
431 bad segments received
46575 resets sent
InCsumErrors: 395
Udp:
258229 packets received
89 packets to unknown port received
0 packet receive errors
271715 packets sent
0 receive buffer errors
0 send buffer errors
UdpLite:
TcpExt:
23716 resets received for embryonic SYN_RECV sockets
7 ICMP packets dropped because they were out-of-window
38835 TCP sockets finished time wait in fast timer
1428 delayed acks sent
Quick ack mode was activated 275 times
105641 packet headers predicted
66845 acknowledgments not containing data payload received
154479 predicted acknowledgments
1 times recovered from packet loss due to fast retransmit
TCPSackRecovery: 156
Detected reordering 56 times using SACK
Detected reordering 8 times using reno fast retransmit
1 congestion windows fully recovered without slow start
TCPDSACKUndo: 75
7 congestion windows recovered without slow start after partial ack
TCPLostRetransmit: 218
TCPSackFailures: 4
2 timeouts in loss state
331 fast retransmits
1 retransmits in slow start
TCPTimeouts: 2934
TCPLossProbes: 289
TCPLossProbeRecovery: 46
TCPSackRecoveryFail: 4
TCPBacklogCoalesce: 746
TCPDSACKOldSent: 278
TCPDSACKRecv: 169
TCPDSACKOfoRecv: 47
71 connections reset due to unexpected data
253 connections reset due to early user close
40 connections aborted due to timeout
TCPDSACKIgnoredNoUndo: 51
TCPSackShifted: 1710
TCPSackMerged: 244
TCPSackShiftFallback: 257
TCPRcvCoalesce: 43172
TCPOFOQueue: 13350
TCPOFOMerge: 27
TCPChallengeACK: 41
TCPSYNChallenge: 38
TCPAutoCorking: 1451
TCPFromZeroWindowAdv: 1
TCPToZeroWindowAdv: 1
TCPWantZeroWindowAdv: 200
TCPSynRetrans: 2051
TCPOrigDataSent: 378682
TCPHystartTrainDetect: 1
TCPHystartTrainCwnd: 17
TCPHystartDelayDetect: 2
TCPHystartDelayCwnd: 2617
TCPACKSkippedSynRecv: 1
TCPKeepAlive: 603
TCPDelivered: 421633
TCPAckCompressed: 6924
TcpTimeoutRehash: 439
TcpDuplicateDataRehash: 34
TCPDSACKRecvSegs: 216
IpExt:
InOctets: 637501815
OutOctets: 200810317
InNoECTPkts: 1312537
MPTcpExt:
显示监听的套接口
root@jdit:~# netstat -l
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 localhost:6010 0.0.0.0:* LISTEN
tcp 0 0 localhost:domain 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:redis 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:ssh 0.0.0.0:* LISTEN
tcp6 0 0 [::]:redis [::]:* LISTEN
udp 0 0 localhost:domain 0.0.0.0:*
udp 0 0 iZ2ze1w1u469cd5g:bootpc 0.0.0.0:*
udp 0 0 localhost:323 0.0.0.0:*
udp6 0 0 ip6-localhost:323 [::]:*
raw6 0 0 [::]:ipv6-icmp [::]:* 7
Active UNIX domain sockets (only servers)
Proto RefCnt Flags Type State I-Node Path
unix 2 [ ACC ] STREAM LISTENING 110292 /run/user/0/systemd/private
unix 2 [ ACC ] STREAM LISTENING 110861 /run/user/0/bus
unix 2 [ ACC ] STREAM LISTENING 17485 @/org/kernel/linux/storage/multipathd
unix 2 [ ACC ] STREAM LISTENING 110863 /run/user/0/gnupg/S.dirmngr
unix 2 [ ACC ] STREAM LISTENING 110865 /run/user/0/gnupg/S.gpg-agent.browser
unix 2 [ ACC ] STREAM LISTENING 110867 /run/user/0/gnupg/S.gpg-agent.extra
unix 2 [ ACC ] STREAM LISTENING 110869 /run/user/0/gnupg/S.gpg-agent.ssh
unix 2 [ ACC ] STREAM LISTENING 110871 /run/user/0/gnupg/S.gpg-agent
unix 2 [ ACC ] STREAM LISTENING 110873 /run/user/0/pk-debconf-socket
unix 2 [ ACC ] STREAM LISTENING 110875 /run/user/0/snapd-session-agent.socket
unix 2 [ ACC ] STREAM LISTENING 20184 /var/snap/lxd/common/lxd/unix.socket
unix 2 [ ACC ] STREAM LISTENING 57267 /run/systemd/private
unix 2 [ ACC ] STREAM LISTENING 56315 /run/systemd/userdb/io.systemd.DynamicUser
unix 2 [ ACC ] STREAM LISTENING 56316 /run/systemd/io.system.ManagedOOM
unix 2 [ ACC ] STREAM LISTENING 225419 /usr/local/aegis/Aegis-<Guid(5A2C30A2-A87D-490A-9281-6765EDAD7CBA)>
unix 2 [ ACC ] STREAM LISTENING 57515 /run/systemd/journal/io.systemd.journal
unix 2 [ ACC ] STREAM LISTENING 24904 /tmp/aliyun_assist_service.sock
unix 2 [ ACC ] STREAM LISTENING 20181 /run/dbus/system_bus_socket
unix 2 [ ACC ] STREAM LISTENING 20188 /run/snapd.socket
unix 2 [ ACC ] STREAM LISTENING 20190 /run/snapd-snap.socket
unix 2 [ ACC ] STREAM LISTENING 20779 /run/uuidd/request
unix 2 [ ACC ] STREAM LISTENING 20186 /var/snap/lxd/common/lxd-user/unix.socket
unix 2 [ ACC ] STREAM LISTENING 20183 @ISCSIADM_ABSTRACT_NAMESPACE
unix 2 [ ACC ] STREAM LISTENING 17387 /run/lvm/lvmpolld.socket
unix 2 [ ACC ] STREAM LISTENING 17488 /run/systemd/fsck.progress
unix 2 [ ACC ] STREAM LISTENING 17393 /run/systemd/journal/stdout
unix 2 [ ACC ] SEQPACKET LISTENING 17396 /run/udev/control
unix 2 [ ACC ] STREAM LISTENING 573784 /run/systemd/resolve/io.systemd.Resolve
