对 Linux 专家非常有用的 20 个命令

rolandyex · 2013 年8 月 11 日 12:08

在这篇文章中我将解释管理 Linux 服务器所需的一些命令。
41. 命令: ifconfig

ifconfig用来配置常驻内核的网络接口信息。在系统启动必要时用来设置网络适配器的信息。之后，它通常是只需要在调试时或当系统需要调整时使用。

检查活动网络适配器

[avishek@tecmint ~]$ ifconfig 

eth0      Link encap:Ethernet  HWaddr 40:2C:F4:EA:CF:0E  
   inet addr:192.168.1.3  Bcast:192.168.1.255  Mask:255.255.255.0 
   inet6 addr: fe80::422c:f4ff:feea:cf0e/64 Scope:Link 
   UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1 
   RX packets:163843 errors:0 dropped:0 overruns:0 frame:0 
   TX packets:124990 errors:0 dropped:0 overruns:0 carrier:0 
   collisions:0 txqueuelen:1000 
   RX bytes:154389832 (147.2 MiB)  TX bytes:65085817 (62.0 MiB) 
   Interrupt:20 Memory:f7100000-f7120000 

lo        Link encap:Local Loopback  
   inet addr:127.0.0.1  Mask:255.0.0.0 
   inet6 addr: ::1/128 Scope:Host 
   UP LOOPBACK RUNNING  MTU:16436  Metric:1 
   RX packets:78 errors:0 dropped:0 overruns:0 frame:0 
   TX packets:78 errors:0 dropped:0 overruns:0 carrier:0 
   collisions:0 txqueuelen:0 
   RX bytes:4186 (4.0 KiB)  TX bytes:4186 (4.0 KiB)

检查所有的网络适配器

“-a”参数用来显示所有网络适配器(网卡)的详细信息,包括那些停用的适配器。

[avishek@tecmint ~]$ ifconfig -a

eth0      Link encap:Ethernet  HWaddr 40:2C:F4:EA:CF:0E  
   inet addr:192.168.1.3  Bcast:192.168.1.255  Mask:255.255.255.0 
   inet6 addr: fe80::422c:f4ff:feea:cf0e/64 Scope:Link 
   UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1 
   RX packets:163843 errors:0 dropped:0 overruns:0 frame:0 
   TX packets:124990 errors:0 dropped:0 overruns:0 carrier:0 
   collisions:0 txqueuelen:1000 
   RX bytes:154389832 (147.2 MiB)  TX bytes:65085817 (62.0 MiB) 
   Interrupt:20 Memory:f7100000-f7120000 

lo        Link encap:Local Loopback  
   inet addr:127.0.0.1  Mask:255.0.0.0 
   inet6 addr: ::1/128 Scope:Host 
   UP LOOPBACK RUNNING  MTU:16436  Metric:1 
   RX packets:78 errors:0 dropped:0 overruns:0 frame:0 
   TX packets:78 errors:0 dropped:0 overruns:0 carrier:0 
   collisions:0 txqueuelen:0 
   RX bytes:4186 (4.0 KiB)  TX bytes:4186 (4.0 KiB) 

virbr0    Link encap:Ethernet  HWaddr 0e:30:a3:3a:bf:03  
   inet addr:192.168.122.1  Bcast:192.168.122.255  Mask:255.255.255.0
   UP BROADCAST MULTICAST  MTU:1500  Metric:1
   RX packets:0 errors:0 dropped:0 overruns:0 frame:0
   TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
   collisions:0 txqueuelen:0 
   RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

停用网络适配器

[avishek@tecmint ~]$ ifconfig eth0 down

启用网络适配器

[avishek@tecmint ~]$ ifconfig eth0 up

指定IP地址到网络适配器

为网络适配器eth0设定IP地址“192.168.1.12”.

[avishek@tecmint ~]$ ifconfig eth0 192.168.1.12

更改网络适配器eth0的子网掩码

[avishek@tecmint ~]$ ifconfig eth0 netmask 255.255.255.

更改网络适配器eth0的广播地址

[avishek@tecmint ~]$ ifconfig eth0 broadcast 192.168.1.255

为网络适配器eth0指定IP地址,子网掩码，广播地址

[avishek@tecmint ~]$ ifconfig eth0 192.168.1.12 netmask 255.255.255.0 broadcast 192.168.1.255

注Note: 如果你设置一块无线网卡的信息,你可以使用的命令是“iwconfig”.欲知更多ifconfig命令的例子和使用方法，读“15个有用的ifconfig 命令”.

rolandyex · 2013 年8 月 11 日 12:09

命令: netstat

netstat命令显示各种网络相关的信息，如网络连接,路由表,接口统计,伪装连接,组播成员身份等…

列出所有的网络端口

[avishek@tecmint ~]$ netstat -a

Active UNIX domain sockets (servers and established)
Proto RefCnt Flags Type State I-Node Path
unix 2 [ ACC ] STREAM LISTENING 741379 /run/user/user1/keyring-I5cn1c/gpg
unix 2 [ ACC ] STREAM LISTENING 8965 /var/run/acpid.socket
unix 2 [ ACC ] STREAM LISTENING 18584 /tmp/.X11-unix/X0
unix 2 [ ACC ] STREAM LISTENING 741385 /run/user/user1/keyring-I5cn1c/ssh
unix 2 [ ACC ] STREAM LISTENING 741387 /run/user/user1/keyring-I5cn1c/pkcs11
unix 2 [ ACC ] STREAM LISTENING 20242 @/tmp/dbus-ghtTjuPN46
unix 2 [ ACC ] STREAM LISTENING 13332 /var/run/samba/winbindd_privileged/pipe
unix 2 [ ACC ] STREAM LISTENING 13331 /tmp/.winbindd/pipe
unix 2 [ ACC ] STREAM LISTENING 11030 /var/run/mysqld/mysqld.sock
unix 2 [ ACC ] STREAM LISTENING 19308 /tmp/ssh-qnZadSgJAbqd/agent.3221
unix 2 [ ACC ] STREAM LISTENING 436781 /tmp/HotShots
unix 2 [ ACC ] STREAM LISTENING 46110 /run/user/ravisaive/pulse/native
unix 2 [ ACC ] STREAM LISTENING 19310 /tmp/gpg-zfE9YT/S.gpg-agent
…

显示所有tcp相关端口

[avishek@tecmint ~]$ netstat -at

Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 localhost:mysql : LISTEN
tcp 0 0 *:5901 : LISTEN
tcp 0 0 *:5902 : LISTEN
tcp 0 0 *:x11-1 : LISTEN
tcp 0 0 *:x11-2 : LISTEN
tcp 0 0 *:5938 : LISTEN
tcp 0 0 localhost:5940 : LISTEN
tcp 0 0 ravisaive-OptiPl:domain : LISTEN
tcp 0 0 ravisaive-OptiPl:domain : LISTEN
tcp 0 0 localhost:ipp : LISTEN
tcp 0 0 ravisaive-OptiPle:48270 ec2-23-21-236-70.c:http ESTABLISHED
tcp 0 0 ravisaive-OptiPle:48272 ec2-23-21-236-70.c:http TIME_WAIT
tcp 0 0 ravisaive-OptiPle:48421 bom03s01-in-f22.1:https ESTABLISHED
tcp 0 0 ravisaive-OptiPle:48269 ec2-23-21-236-70.c:http ESTABLISHED
tcp 0 0 ravisaive-OptiPle:39084 channel-ecmp-06-f:https ESTABLISHED
…

显示所有连接的统计信息

[avishek@tecmint ~]$ netstat -s

Ip:
4994239 total packets received
0 forwarded
0 incoming packets discarded
4165741 incoming packets delivered
3248924 requests sent out
8 outgoing packets dropped
Icmp:
29460 ICMP messages received
566 input ICMP message failed.
ICMP input histogram:
destination unreachable: 98
redirects: 29362
2918 ICMP messages sent
0 ICMP messages failed
ICMP output histogram:
destination unreachable: 2918
IcmpMsg:
InType3: 98
InType5: 29362
OutType3: 2918
Tcp:
94533 active connections openings
23 passive connection openings
5870 failed connection attempts
7194 connection resets received
…

好的！由于某些原因如果你不想解析netstat 输出的主机、端口和用户名称的话。

[avishek@tecmint ~]$ netstat -an

好，你可能需要获取的 netstat 持续输出的动态信息，通过传递中断输出指令 (ctrl + c)来停止。

[avishek@tecmint ~]$ netstat -c

更多关于“netstat”的例子和使用方法，浏览文章“20个netstat 的使用案例”。

rolandyex · 2013 年8 月 11 日 12:10

命令： nslookup

网络实用程序，用于获得互联网服务器的信息。顾名思义，该实用程序将发现通过查询 DNS 域的名称服务器信息。

[avishek@tecmint ~]$ nslookup tecmint.com