industrial network protocols

The data link layer has three main purposes: * Sends and accepts IP data packets for the IP module; * Send ARP requests to the ARP module and receive ARP responses; * Send RARP requests and RARP responses to RARP. The ARP protocol is mainly used to resolve the 32bit IP address to the MAC address (hardware address) corresponding to the 48bit (Ethernet ). The RARP protocol resolves the hardware address to an IP address. The two protocols are at the

20.1. webbrowser -convenient Web-browser Controller 20.2. cgi -common Gateway Interface Support 20.3. cgitb -traceback Manager for CGI scripts 20.4. wsgiref -wsgi Utilities and Reference implementation 20.5. urllib -open arbitrary resources by URL 20.6. urllib2 -extensible Library for opening URLs 20.7. httplib -http Protocol Client 20.8. ftplib -FTP Protocol Client 20.9. poplib -POP3 Protocol Client 20.10. imaplib -IMAP4 Protocol Client 20.11. nntplib -NNTP Protocol Client

Network protocols play an important role in movie servers. It can be said that without network protocols, movie servers will not be able to play a normal role. This article briefly introduces several mainstream network protocols,

Every time you write and design a network communication program, you always have to deal with the problem of customizing a set of application protocols (that is, communication protocols) and then writing corresponding methods to parse the protocols, and provides corresponding interfaces for upper-layer calls. It is eas

-scale network environments. The RIP protocol is used to transmit route information in an AS autonomous system. Route information is updated every 30 seconds. The RIP Protocol provides hop count to measure the route distance, the hop count is the number of routers required for a packet to reach the target. The maximum number of hops supported by RIP is 15. Application: in Windows, we can enable the "RIP listener" function to listen to RIP messages, so

1. What is the difference between web1.0,web2.0,web3.0?web1.0: Information-seekers and consumers, information created by website operatorsweb2.0: User-created content (Ugc:user generated content, forums, Weibo, video sharing, classified information)web3.0: Users get content on demand, RSS feeds, zaker subscriptions, hot spots today2. What is the difference between Hypertext Markup Language Hyper Text Markup Language (html4,5)?HTML4 If you want to play a video, you must install a video player, su

Source: http://support.microsoft.com/ SummaryInternet Protocol Security (IPSec) filtering rules can be used to protect Windows 2000-based computers from web-based attacks caused by viruses, worms, and other threats. This article describes how to filter out specific protocol and port combinations for inbound and outbound network communication. This document also includes steps for determining whether an IPSec Policy is specified for a Windows 2000-base

target path next to a neighboring router. Each router is removed and the new data link layer information is added before forwarding.6. Data is transmitted over the Internet, including media and intermediary equipment. The 7.client receives a data link frame that includes data. Handles each layer of protocol headers, and then removes the protocol headers in the reverse order of accession. First, the Ethernet information is processed and removed. The IP protocol information is followed. The next

I have read more than just some introductory articles. At least I have downloaded the standard protocol document and read more than the overview part :) Some protocols have participated in the development of commercial products; Some are just some of the implementations of open source code; Some, just look at it and understand the design ideas of the Protocol. Instant messaging (IM) (Once circulated on the InternetJabber technical White PaperAndPro

The driving force of technological development is the constant demand of people. With the increasing use of the Internet, the current network protocol version is no longer able to meet the needs of the times. Inevitably, we will launch a new generation of IPv6 network protocols that are more complete and have diverse functions. The inevitable elimination of IPv4

We all know that computer networks are divided into seven layers, each of which has its own network communication protocol. We can easily understand the concept of network communication protocol. However, it contains many protocols. Here we will summarize several important protocols to help you make a summary. See the

TPC/IP protocol is a Transport layer protocol, which mainly solves how data is transmitted in the network, and HTTP is the application layer protocol, which mainly solves how to wrap the data.Regarding the relationship between TCP/IP and HTTP protocol, the network has a relatively easy to understand introduction:"When we transmit data, we can only use the (Transport Layer) TCP/IP protocol, but in that case,

the address type to be converted, and 0x0800 is the IP address, the length of the following two addresses is 6 and 4 (bytes) for the ethernet address and IP address respectively. The op field is 1, indicating the ARP request, and the OP field is 2, indicating the ARP response. The process of the Address Resolution Protocol is as follows: Iv. RARP (Reverse Address Resolution Protocol) The opposite of ARP is mainly used to obtain the IP address of a diskless workstation, as shown in. 5. ICMP

artificially banned, so there are other mechanisms that can still pass SessionID back to the server when the cookie is banned. This technique is called URL rewriting, that is, the SessionID directly appended to the URL path, there are two additional ways, one is as the URL path of additional information, the representation of http://www.wantsoft.com/index.asp; Jsessionid= byok3vjfd75apnrf7c2hmdnv6qzcebzwowibyenlerjq99zwpbng!-145788764.The other is appended to the URL as a query string, in the f

Common ping command protocols in the Network Network Protocol Network Firewall Router ICMP is the abbreviation of "Internet Control Message Ptotocol" (Internet Control Message Protocol. It is a sub-Protocol of the TCP/IP protocol family. It is used to transmit control messages between IP hosts and routers. A message c

ICMP is the so-called Internet Control Messaging Protocol (PROTOCOL), which is commonly used to transmit error messages and other information that should be noted in the network. ICMP is generally considered to be the same level as the IP protocol, IMCP packets are usually used by IP layer or higher level protocol (such as TCP or UDP), ICMP for the internet and other ip-based network based on the normal ope

This article describes the first example: five simple TCP Network service protocols, including Echo (RFC 862), Discard (RFC 863), Chargen (RFC 864), Daytime (RFC 867), Time (RFC 868), and time The client of the Protocol. The functions of each agreement are as follows: * Discard-discard all data received; * Daytime-service-side accept connection, send the current time as a string, and then actively disconn

files and their protocols. Note: Here said that send, receive file is standing in the position of the client said, when the client sent the file, for the server to collect, is to receive files. 1.2 Receiving files The receiving file is actually exactly the same as sending the file, except that the client writes data to the network stream or the server writes the data to the

1 encapsulation process when data enters the protocol stack650) this.width=650; "title=" Fz.png "alt=" wkiom1v_36hx7bcuaadxid3fsmq859.jpg "src=" http://s3.51cto.com/wyfs02/M02/ 6e/93/wkiom1v_36hx7bcuaadxid3fsmq859.jpg "/>2 Layer four network model for TCP/IP protocol:650) this.width=650; "title=" 44444.png "alt=" wkiol1v_3-qz4n2_aac4dkekcaw688.jpg "src=" http://s3.51cto.com/wyfs02/ M02/6e/8e/wkiol1v_3-qz4n2_aac4dkekcaw688.jpg "/>This article is from t