dgram

Node. js development-UDP Programming Node. js also provides UDP programming capabilities.DgramModule. Unlike TCP, UDP is connectionless and does not guarantee data reliability. However, its programming is simpler and sometimes we need it. For example, for APP statistics, logs, or streaming media, many streaming media protocols use UDP, and a lot of data is searched on the Internet. If you want to send data using UDP, you only need to know the host name (address) and port number of the other part

, such as Eth0,eth1,eth2).NetstatThis command is a command that displays the various circumstances of the network, and will represent active Internet connections and Activeunix domain sockets in cases where no parameters are executed.Check out the following output information:This is the case where 192.168.1.56 is connecting to 192.168.1.81 via SSH[Root@linux ~] #netstatActive internetconnections (w/o servers)Proto recv-q send-qlocal Address foreignaddress StateTCP 0 0:: Ffff:192.168.1.81:ssh::

2 [] DGRAM 1491 @/org/kernel/udev/udevdUnix 4 [] DGRAM 7337/dev/logUnix 2 [] DGRAM 708823Unix 2 [] DGRAM 7539Unix 3 [] stream connected 7287.Unix 3 [] stream connected 7286.[Root @ localhost ~] # Note: The output result of netstat can be divided into two parts: One is Active Internet connections, which is called an Ac

node. JS also provides the ability to program UDP, and the related libraries are in the "dgram" module.Unlike TCP, UDP is non-connected and does not guarantee the reliability of the data, but its programming is simpler and sometimes we need it. such as the statistics of the app or log or streaming media, a lot of streaming protocols will use UDP, a large number of online search.Using UDP, if you want to send data, just need to know the host name (addr

services, such as ftp, telnet, shell, login, exec, talk, ntalk, imap, pop-2, pop-3, finger, and auth, and so on. If you find some services useful, do not disable them. However, if these services are disabled, the system may be more vulnerable to attacks. The content of the changed "inetd. conf" file is shown below: # To re-read this file after changes, just do a 'killall-HUP inetd' # # Echo stream tcp nowait root internal # Echo dgram udp

connections (w/o servers) Proto Recv-Q Send-Q Local Address Foreign Address State Tcp 0 252 192.168.1.222: 22 192.168.1.223: 3532 ESTABLISHED Active UNIX domain sockets (w/o servers) Proto RefCnt Flags Type State I-Node Path For unix 9 [] DGRAM 436/dev/log Unix 0 [] stream connected 177 @ 00000016 Unix 0 [] DGRAM 771 Unix 0 [] DGRAM 753 Unix 0 []

Linux-based netstat command introduction the Netstat command is used to display various network-related information, such as network connection, route table, interface status (InterfaceStatistics), masquerade connection, and multicast member (MulticastMemberships. Execute nets for the output information... linux-based netstat command introduction the Netstat command is used to display various network-related information, such as network connection, route table, Interface status (Interface Statis

Linux-based netstat command Introduction The Netstat command is used to display various network-related information, such as network connection, route table, Interface status (Interface Statistics), masquerade connection, and Multicast member (Multicast Memberships. Output Information meaning after netstat is executed, the output result is [plain] [root @ localhost ~] # Netstat Active Internet connections (w/o servers) Proto Recv-Q Send-Q Local Address Foreign Address State getnameinfo failed tc

, and auth, and so on.If you find some services useful, do not disable them. However, if these services are disabled, the system may be more vulnerable to attacks. The content of the changed "inetd. conf" file is shown below: the content is from www.chinahtml.com)# To re-read this file after changes, just do a 'killall-HUP inetd'# # Echo stream tcp nowait root internal# Echo dgram udp wait root internal# Discard stream tcp nowait roo

nowait root internal #echo dgram UDP Wait root internal #discard Stream TCP nowait root internal #discard dgram UDP Wait root internal #daytime Stream TCP nowait root internal #daytime dgram UDP Wait root internal #chargen Stream TCP nowait root internal #chargen dgram UDP Wait root internal #time Stream TCP n

prohibit all unwanted services, such as FTP, Telnet, shell, login, exec, talk, Ntalk, IMAP, POP-2, pop-3, Finger, auth, and so on. If you feel that some services are useful, you may not ban these services. However, by banning these services, the system is less likely to be attacked. The contents of the changed "inetd.conf" file are as follows: # to re-read this file after the changes, just do a ' killall-hup inetd ' # #echo Stream TCP nowait root internal #echo

IntroductionThe Netstat command is used to display various network-related information, such as network connections, routing tables, Interface states (Interface Statistics), masquerade connections, multicast members (multicast memberships), and so on.output message meaningAfter executing the netstat, the output isActive Internet connections (w/o servers) Proto recv-q send-q Local address Foreign address statetcp 0 2 210.34.6.89:telnet 210.34.6.96:2873 establishedtcp 296 0 210.34.6.89:1165 210.34

work information.-T or –tcp shows the connection status of the TCP transport protocol.-U or –UDP shows the connection status of the UDP transport protocol.-V or –verbose shows the instruction execution process.-V or –version displays version information.-W or –raw shows the connection status of the raw transport protocol.-X or –unix the effect of this parameter is the same as specifying the "-A Unix" parameter.– IP or –inet the effect of this parameter is the same as specifying the "-A inet" pa

monitoring TCP/IP networks, displaying routing tables, actual network connections, and status information for each network interface device. After the Netstat is executed on the computer, its output looks like this: ----------------------------------------------------------------- [Root@lee/root] #netstat Active Internet connections (w/o servers) Proto recv-q send-q Local address Foreign Active UNIX domain sockets (w/o servers) Proto refcnt Flags Types State I-node Path Unix 5 []

Features and applications of the 1.UDP protocol.Although UDP transmission data is unreliable, no connection, but has the characteristics of fast transmission, in the transmission of audio, video, pictures, less data harmless, you can consider using UDP.How UDP in the 2.node.js should be used.The UDP module in node. js is ' Dgram ', referencing the UDP module and creating a UDP application instance in the following way:var

Article Title: Build the davinci platform for tftp development under Ubuntu8.04. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source. 1. Install tftp and tftpd. The former is the client and the latter is the server. Because tftp requires inetd for control, and the ubuntu system does not install inetd by default, install it. (I failed for the first time because the

The OSI seven-layer model is a standard system and framework for interconnection between different computers or communication systems, including a range of standards and protocols in OSI, such as TCP/IP, UDP, HTTP, and so on, which provide implementation and support for these protocols in Node.js, such as: NET modules provide TCP, Socket encapsulation and support, the Dgram module provides a package and support for UDP, the HTTP module further encapsu

output shows only the SysV service and does not contain the native SYSTEMD service. SysV configuration data may be overwritten by native SYSTEMD configuration. If you want to list the SYSTEMD service, please do'Systemctl list-unit-files'. To view services enabled for a specific target, perform'systemctl list-dependencies [target]'. Netconsole0: Off1: Off2: Off3: Off4: Off5: Off6: Close Network0: Off1: Off2: Open3: Open4: Open5: Open6: Off XINETD-based services: Chargen-