Linux netstat命令详解和使用例子（显示各种网络相关信息）(3)
代码如下: [root@localhost ~]# netstat -s Ip: 530999 total packets received 0 forwarded 0 incoming packets discarded 530999 incoming packets delivered 8258 requests sent out 1 dropped because of mi
代码如下:
[root@localhost ~]# netstat -s
Ip:
530999 total packets received
0 forwarded
0 incoming packets discarded
530999 incoming packets delivered
8258 requests sent out
1 dropped because of missing route
Icmp:
90 ICMP messages received
0 input ICMP message failed.
ICMP input histogram:
destination unreachable: 17
echo requests: 1
echo replies: 72
106 ICMP messages sent
0 ICMP messages failed
ICMP output histogram:
destination unreachable: 8
echo request: 97
echo replies: 1
IcmpMsg:
InType0: 72
InType3: 17
InType8: 1
OutType0: 1
OutType3: 8
OutType8: 97
Tcp:
8 active connections openings
15 passive connection openings
8 failed connection attempts
3 connection resets received
1 connections established
3132 segments received
2617 segments send out
53 segments retransmited
0 bad segments received.
252 resets sent
Udp:
0 packets received
0 packets to unknown port received.
0 packet receive errors
5482 packets sent
TcpExt:
1 invalid SYN cookies received
1 TCP sockets finished time wait in fast timer
57 delayed acks sent
Quick ack mode was activated 50 times
60 packets directly queued to recvmsg prequeue.
68 packets directly received from backlog
4399 packets directly received from prequeue
520 packets header predicted
51 packets header predicted and directly queued to user
1194 acknowledgments not containing data received
21 predicted acknowledgments
0 TCP data loss events
1 timeouts after reno fast retransmit
9 retransmits in slow start
42 other TCP timeouts
3 connections aborted due to timeout
IpExt:
InBcastPkts: 527777
说明：
按照各个协议分别显示其统计数据。如果我们的应用程序（如Web浏览器）运行速度比较慢，或者不能显示Web页之类的数据，那么我们就可以用本选项来查看一下所显示的信息。我们需要仔细查看统计数据的各行，找到出错的关键字，进而确定问题所在。
实例8：显示监听的套接口
命令：netstat -l
输出：
代码如下:
[root@localhost ~]# netstat -l
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 localhost:smux *:* LISTEN
tcp 0 0 *:svn *:* LISTEN
tcp 0 0 *:ssh *:* LISTEN
udp 0 0 localhost:syslog *:*
udp 0 0 *:snmp *:*
Active UNIX domain sockets (only servers)
Proto RefCnt Flags Type State I-Node Path
unix 2 [ ACC ] STREAM LISTENING 708833 /tmp/ssh-yKnDB15725/agent.15725
unix 2 [ ACC ] STREAM LISTENING 7296 /var/run/audispd_events
[root@localhost ~]#
实例9：显示所有已建立的有效连接
命令：netstat -n
输出：
代码如下:
[root@localhost ~]# netstat -n
Active Internet connections (w/o servers)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 268 192.168.120.204:22 10.2.0.68:62420 ESTABLISHED
Active UNIX domain sockets (w/o servers)
Proto RefCnt Flags Type State I-Node Path
unix 2 [ ] DGRAM 1491 @/org/kernel/udev/udevd
unix 4 [ ] DGRAM 7337 /dev/log
unix 2 [ ] DGRAM 708823
unix 2 [ ] DGRAM 7539
unix 3 [ ] STREAM CONNECTED 7287
unix 3 [ ] STREAM CONNECTED 7286
[root@localhost ~]#
实例10：显示关于以太网的统计数据
命令：netstat -e
输出：
代码如下:
[root@localhost ~]# netstat -e
Active Internet connections (w/o servers)
Proto Recv-Q Send-Q Local Address Foreign Address State User Inode
tcp 0 248 192.168.120.204:ssh 10.2.0.68:62420 ESTABLISHED root 708795
Active UNIX domain sockets (w/o servers)
Proto RefCnt Flags Type State I-Node Path
unix 2 [ ] DGRAM 1491 @/org/kernel/udev/udevd
unix 4 [ ] DGRAM 7337 /dev/log
unix 2 [ ] DGRAM 708823
unix 2 [ ] DGRAM 7539
unix 3 [ ] STREAM CONNECTED 7287
unix 3 [ ] STREAM CONNECTED 7286
[root@localhost ~]#
说明：
用于显示关于以太网的统计数据。它列出的项目包括传送的数据报的总字节数、错误数、删除数、数据报的数量和广播的数量。这些统计数据既有发送的数据报数量，也有接收的数据报数量。这个选项可以用来统计一些基本的网络流量）
实例11：显示关于路由表的信息
命令：netstat -r
输出：
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