what is packet tracer

the iptables of the user space and the NetFilter-based ip_tables module of the kernel space and the way it communicates, as well as the role NetFilter plays in it.Go back to the five key points discussed earlier about the protocol stack, "ABCDE". NetFilter in the netfilter_ipv4.h the five points to re-name, as shown, meaning I will no longer explain, Cat called Mimi only:At each key point, there are many callback functions that have been pre-registered by priority (and

their communication methods, as well as the role of Netfilter in this figure.Go back to the five key points "ABCDE" discussed earlier on the protocol stack. Netfilter re-names these five points in netfilter_00004.h, as shown in, meaning I will not explain it anymore. The cat is called Mimi:At each key point, there are many callback functions that have been pre-registered by priority (What are these functio

What is the TCP/IP protocol. first, the TCP/IP model The TCP/IP protocol model (transmission Control protocol/internet Protocol) contains a series of network protocols that form the basis of the Internet and is the core protocol of the Internet. The TCP/IP-based Reference model divides the protocol into four tiers, namely the link layer, the network layer, the t

router can filter the layer-2 broadcast because the router is a layer-3 device. If the router does not filter such packets, the layer-2 broadcast packet initiated by anyone will reach the entire Internet range. What else do the router need to do? The router is used to divide the broadcast domain. For layer-3 broadcast

What is Iptables-general Linux technology-Linux technology and application information? For more information, see. Iptables is a packet filtering management tool based on the netfilter architecture. It is mainly used for firewall or transparent proxy. Iptables has evolved fr

reduced. 2. What is the difference between router forwarding data and vswitches? In contrast, a router operates at the network layer in the OSI Layer-7 network model. It receives any packet (including a broadcast packet) in the network ), the second layer (data link layer) information of the data

, the transport layer TCP is based on the network layer of IP protocol, and the application layer of the HTTP protocol is based on the transport layer of the TCP protocol, and the socket itself is not a protocol, as mentioned above, it just provides a TCP or UDP programming interface.Here are some of the important concepts that are often encountered in a written

What is green software and How to Make It (reprinted )-- The author wrote a strong article about green software. Definition and classification of green software After installing the operating system, we usually need to install some commonly used software. However, as the number of commonly used software increases, the installation process becomes increasingly annoying: run setup, and then select the targe

it will be sent.The following methods have been created:Write an encryption method and encrypt it with a timestamp, a random number, and a predefined token (or code). The link to the QR code also carries a random number with a timestamp, and a token, after scanning the QR code, verify the validity of the parameter encryption and the stored encrypted string. This may prevent the url owner from receiving the red packet. Do you have any good ideas? 1

Love to listen to the characteristics of 4G "Telecom 4G users love to listen to 4G in the province of total free flow" [1], love to listen to 4G is the sky Wing love music combined with 4G high-speed features of the network, specifically forMusic enthusiasts carefully crafted music player, so that you listen unimpeded. Ultra-high quality of a large amount of songs, King days after the classic songs, popular trends in film and television songs, the do

I believe that the computer will know that there is a firewall function, then what is the firewall? What does it do? Today we will unveil the mystery of the firewall. Firewalls are usually used for the following purposes: restricting access to the internal network, filtering out unsafe services and illegal

the handshake, the browser initiates an HTTP request (see packet), uses the method GET method of HTTP, the URL of the request is/, the protocol is http/1.0The following is the detailed contents of package number 12th:The above message is an HTTP request message.So

When we enter www.linux178.com in the address bar of the browser, and then go to enter, enter this moment to see what happened to the page?The following procedure is for personal understanding only:Domain name resolution--Initiates a TCP 3 handshake--initiates an HTTP request after the TCP connection is established--the server responds to the HTTP request, the br

Martian Source/martian PacketsIn Linux, by default, packets is considered individually for routing purposes. Thus, all the routing algorithm determines where to send a packet based on this packet itself, without taking into conside Ration that the packet is a response

. It is designed to replace the current HTTP 1.1 protocol. It is said that the performance of SPDY protocol is 1 times faster than HTTP 1.1. SPDY retains the semantics of HTTP 1.1, but the transmission method is different from HTTP 1.1. That is to say, existing Web applicati

What is the process of a complete HTTP transaction? statement: The statement in this article is only a summary of personal understanding, not necessarily completely correct, but can help to understand. For the HTTP protocol, refer to the following: HTTP protocol ramble on Http://kb.cnblogs.com/page/140611/HTTP Protocol Overview http://www.cnb

packet they are Contained in ). Now depending on the decoder, this can be a problem or not (although the mpeg file is not MPEG compliant as there shoshould be no underflows !). Some decoders (most notably PC based Players) read the file as fast as needed to display the video, ignoring the SCR as needed. Note that in the listing you provide, the average video bitrate is