Common Linux commands (6)-Network Communication commands

Common Linux commands (6) -- Network Communication commands 1. command name: writewww.2cto.com execution permission: all users function description: send information to another user, with CTRL + D as the concluding remarks: write & lt; user name & gt; root sends information to the luxh user [root @ l...
Common Linux commands (6) -- Network Communication commands 1. command name: write www.2cto.com execution permission: all users function description: send information to another user, with CTRL + D as the end syntax: write <用户名> Root sends information to the luxh user [root @ localhost ~] # Write luxhwrite: luxh is logged in more than once; writing to pts/1 hello, luxh, I am root user luxh receives the information [luxh @ localhost ~] $ Message from luxh@localhost.localdomain (as root) on pts/0... hello, luxh, I am root user sends messages to the luxh user. the luxh user must have logged in; otherwise, it cannot be sent. 2. command name: wall execution permission: all users function description: Broadcast information syntax to all users: wall [message] [file name] root sends information to all login users [root @ localhost ~] # Wall Happy New Year Broadcast message from root@localhost.localdomain (pts/0) (Thu Nov 22 05:27:49 2012): Happy New Year [root @ localhost ~] # Login users can receive www.2cto.com [luxh @ localhost ~] $ Broadcast message from root@localhost.localdomain (pts/0) (Thu Nov 22 05:27:49 2012): Happy New Year 3, Command Name: ping run permission: root function description: test network connectivity syntax: ping [option] directly ping the IP address in Linux and press CTRL + C to terminate the command. Otherwise, the IP address will be pinged [root @ localhost ~] # Ping 192.168.1.1PING 192.168.1.1 (192.168.1.1) 56 (84) bytes of data.64 bytes from 192.168.1.1: icmp_seq = 1 ttl = 128 time = 6.66 ms64 bytes from 192.168.1.1: icmp_seq = 2 ttl = 128 time = 6.63 ms64 bytes from 192.168.1.1: icmp_seq = 3 ttl = 128 time = 3.13 ms64 bytes from 192.168.1.1: icmp_seq = 4 ttl = 128 time = 4.55 ms64 bytes from 192.168.1.1: icmp_seq = 5 ttl = 128 time = 6.69 ms64 bytes from 192.168.1.1: icmp_seq = 6 ttl = 128 time = 5.90 ms64 bytes from 192.168.1.1: icmp_seq = 7 ttl = 128 time = 2.77 ms64 bytes from 192.168.1.1: icmp_seq = 8 ttl = 128 time = 2.75 ms64 bytes from 192.168.1.1: icmp_seq = 9 ttl = 128 time = 5.41 ms64 bytes from 192.168.1.1: icmp_seq = 10 ttl = 128 time = 7.52 MS use-c to specify the number of ping times [luxh @ localhost ~] $ Ping-c 4 192.168.1.1PING 192.168.1.1 (192.168.1.1) 56 (84) bytes of data.64 bytes from 192.168.1.1: icmp_seq = 1 ttl = 128 time = 6.49 ms64 bytes from 192.168.1.1: icmp_seq = 2 ttl = 128 time = 5.42 ms64 bytes from 192.168.1.1: icmp_seq = 3 ttl = 128 time = 2.46 ms64 bytes from 192.168.1.1: icmp_seq = 4 ttl = 128 time = 3.69 MS --- 192.168.1.1 ping statistics --- 4 packets transmitted, 4 received, 0% packet loss, time 30 10 msrtt min/avg/max/mdev = 2.464/4.520/6.498/1.551 MS [luxh @ localhost ~] $ Use-s to specify the size of the sending package. The maximum size cannot exceed 65507 bytes [root @ localhost ~] # Ping-c 4-s 1024 192.168.1.1PING 192.168.1.1 (192.168.1.1) 1024 (1052) bytes of data.1032 bytes from 192.168.1.1: icmp_seq = 1 ttl = 128 time = 6.67 ms1032 bytes from 192.168.1.1: icmp_seq = 2 ttl = 128 time = 4.21 ms1032 bytes from 192.168.1.1: icmp_seq = 3 ttl = 128 time = 9.06 ms1032 bytes from 192.168.1.1: icmp_seq = 4 ttl = 128 time = 5.09 MS --- 192.168.1.1 ping statistics --- 4 packets transmitted, 4 received, 0% Packet loss, time 3010 msrtt min/avg/max/mdev = 4.212/6.262/9.064/1.845 MS [root @ localhost ~] #4. command name: ifconfig execution permission: root function description: View network settings syntax: ifconfig [-a] [Nic device ID]-a displays information about all NICs (which can be omitted in Linux and cannot be omitted in Unix) [root @ localhost ~] # Ifconfigeth0 Link encap: Ethernet HWaddr 00: 0C: 29: 4C: 63: 3E inet addr: 192.168.0.102 Bcast: 192.168.0.255 Mask: 255.255.255.0 inet6 addr: fe80: 20c: 29ff: fe4c: 633e/64 Scope: Link up broadcast running multicast mtu: 1500 Metric: 1 RX packets: 4238 errors: 0 dropped: 0 overruns: 0 frame: 0 TX packets: 3578 errors: 0 dropped: 0 overruns: 0 carrier: 0 collisions: 0 txqueuelen: 1000 RX bytes: 4560042 (4.3 MiB) TX bytes: 299 603 (292.5 KiB) Interrupt: 19 Base address: 0x2024 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: 8 errors: 0 dropped: 0 overruns: 0 frame: 0 TX packets: 8 errors: 0 dropped: 0 overruns: 0 carrier: 0 collisions: 0 txqueuelen: 0 RX bytes: 480 (480.0 B) TX bytes: 480 (480.0 B) eth0 is the actual physical Nic, lo is the Virtual loopback address. the IP address of the NIC is changed temporarily. it is invalid after restart [Root @ localhost ~] # Ifconfig eth0 192.168.1.5