Shulou(Shulou.com)06/01 Report--

This article mainly introduces "what are the basic commands of Linux network". In the daily operation, I believe that many people have doubts about the basic commands of Linux network. The editor consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful to answer the questions of "what are the basic commands of Linux network?" Next, please follow the editor to study!

List of Linux basic network commands

I use FreeBSD in computer networking courses, but these UNIX commands should also work on Linux.

Connectivity

* * ping: * * send an ICMP echo message (a packet) to the host. This may be sent until you press Control-C,Ping, which means that a packet is sent from your machine through ICMP and echoed at the IP layer. Ping tells you whether another host is running.

Telnet [port]:

Communicate with the host on the specified port. The default telnet port is 23. Press Control-] to exit telnet. Other commonly used ports are:

7-- echo port 25-- SMTP, used to send email 79-- Finger (LCTT translation: Wikipedia-Finger protocal, but the example of Finger may not be appropriate, why not try 80? To provide information about other users under the network ARP

ARP is used to translate IP addresses into Ethernet addresses. Root users can add and delete ARP records. It is useful to delete ARP records when they are contaminated or incorrect. ARP records that are explicitly added by root are permanent-- as are those set by the agent. The ARP table is stored in the kernel and manipulated dynamically. ARP records are cached, usually invalidated and deleted after 20 minutes.

* * arp-an ARP table is printed. * * arp-s [pub]: * * add a record to the table. * * arp-a-d records * deletes all records in the ARP table. The route * * netstat-r _ r prints the routing table. The routing table is stored in the kernel and is used by the IP layer to route packets to non-local networks. Route add:route: used to add static (manually specified rather than dynamic) routing paths to the routing table. All traffic from this PC to that IP/ subnet passes through the specified gateway IP. It can also be used to set a default route. For example, with 0.0.0.0 on the IP/ subnet, all packets can be sent to a specific gateway. * * BSD daemon that controls dynamic routing by routed:**. Start when you turn it on. It runs the RIP routing protocol. Only root users are available. You can't run it without root permission. Gated:gated is another routing daemon that uses the RIP protocol. It supports both OSPF, EGP and RIP protocols. Only root users are available. * * traceroute:** is used to track the routing of IP packets. It increments the hop count by 1 every time it sends a packet, so that all gateways from the source address to the destination will return a message. * * netstat-rnf inet:** displays the routing table of IPv4. * * sysctl net.inet.ip.forwarding=1:** enables packet forwarding (turning the host into a router). Route add | delete [- net |-host]: (for example, route add 192.168.20.0 Universe 24 192.168.30.4) add a route. * * route flush:** deletes all routes. * * route add-net 0.0.0.0 192.168.10.2 virtual route * add a default route. * * routed-Pripv2-Pno_rdisc-d [- s |-Q]: * * run routed daemon, use RIPv2 protocol, do not enable ICMP automatic discovery, run in foreground, supply mode or quiet mode. * * route add 224.0.0.0Unigram 4 127.0.0.1 routes * defines a multicast route for the local address. (LCTT translation note: original text is in doubt) * * rtquery-n (LCTT translation note: added host parameter): * * query the RIP daemon on the specified host (manually update the routing table). Other nslookup:** queries the DNS server to change the IP to a name, or vice versa. For example, nslookup facebook.com gives the IP of facebook.com. * * ftp [port] (LCTT translation note: water should be a clerical error): * * transfer the file to the specified host. You can usually use the login name "anonymous" and the password "guest" to log in. * * rlogin-l (LCTT added host parameter): * * log in to the host using a virtual terminal similar to telnet. Mapping of important file * * / etc/hosts:** domain names to IP addresses. * * / etc/networks:** network name to IP address mapping. * * / etc/protocols:** protocol name to protocol number mapping. * * / etc/services:**TCP/UDP service name to port number mapping. Tools and network performance analysis * * ifconfig [up]: * * start the interface. * * ifconfig [down | delete]: * * stop the API. * * ethereal & : * * Open ethereal in the background instead of the foreground. * * tcpdump-I-vvv: * * tools for crawling and analyzing packages. * * netstat-w [seconds]-I [interface]: * * displays network settings and statistics. * * udpmt-p [port]-s [bytes] target_host: * * send UDP traffic. * * udptarget-p [port]: * * receive UDP traffic. * * tcpmt-p [port]-s [bytes] target_host: * * send TCP traffic. * * tcptarget-p [port]: * * receive TCP traffic. Switch * * ifconfig sl0 srcIP dstIP ifconfig sl0 srcIP dstIP:** configures a serial interface (slattach-l / dev/ttyd0 before, followed by sysctl net.inet.ip.forwarding=1) * * telnet 192.168.0.254 sysctl net.inet.ip.forwarding=1 access the switch from a host in the subnet. * * sh ru or show running-configuration: * * View the current configuration. * * configure terminal: * * enter configuration mode. * * exit: * * exit the current mode. (LCTT translation note: the original text is doubtful) VLAN** vlan n: * * create a VLAN with ID n. * * no vlan N: * * Delete the VLAN with n ID. * * untagged Y: * * add port Y to VLAN n. * * ifconfig vlan0 create: * * create an vlan0 API. * * ifconfig vlan0 vlan_ID vlandev em0:** adds em0 to the vlan0 interface and marks it as ID. * * ifconfig vlan0 [up]: * * enable virtual interface. * * tagged Y: * * add tagged frame support for port Y of the current VLAN. UDP/TCP** A socklab udp: * * run socklab using the UDP protocol. * * sock: * * create a UDP socket, which is equivalent to typing sock udp and bind. * * sendto:** sends packets. * * recvfrom:** receives data from sockets. * * socklab tcp: * * run socklab using TCP protocol. * * passive passive:** creates a passive mode socket, which is equivalent to socklab, sock tcp, bind, listen. * * accept: * * incoming connections are accepted (can be performed before or after initiating incoming connections). * * connect:** is equivalent to socklab, sock tcp, bind, and connect. * * close: * * close the connection. * * read:** reads n bytes from the socket. Write: (for example, write ciao, write # 10) writes "ciao" or 10 bytes to the socket. NAT/ firewall * * rm / etc/resolv.conf: * * disable address resolution to ensure that your filtering and firewall rules work correctly. * * ipnat-f file_name: * * write the filtering rules to the file. * * ipnat-l: * * displays a list of active rules. * * ipnat-C-F: * * reinitialize the rule table. * * map em0 192.168.1.0 em0:** 24-> 195.221.227.57 em0:** maps the IP address to the interface. * * map em0 192.168.1.0 map em0 24-> 195.221.227.57Uniple 32 portmap tcp/udp 20000 50000 * Mapping with port number. * * ipf-f file_name: * * write the filtering rules to the file. * * ipf-F-a: * * reset the rule table. * * ipfstat-I: * * lists the status entries of the activity when used with the-s option (LCTT translation note: the original text is in doubt). At this point, the study of "what are the basic commands of Linux network" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.