what is packet tracer

　　1, what is the gateway According to different classification criteria, there are many kinds of gateways. The gateway in the TCP/IP protocol is the most commonly used, where we speak of "gateways" that refer to the TCP/IP protocol gateway. What is a gateway? A gateway

Click to enter _ more _java thousand ask1. What is the JDK base extension class library?See the Java core Framework here: What is the Java core framework?The JDK base Class library is divided into two parts, the base library, the extended base library, and provides a conside

socket and client communication. (Note: The server-side listening port is unchanged, but the socket connection can be generated and one thread corresponds to a socket.) at the same time, a port can only establish one connection. NBSP Listening on a port, but while listening to the port, the generation of a waiting queue, each from the client's connection will be sent to the waiting queue, the server uses a certain algorithm to select the correspon

The recent Alexa to domestic site punishment farce has always been a lonely people out of the commotion, most people are saying or vague that the domestic such as cool news, post easy, popcorn and the like "because many Chinese Internet practitioners blindly pursue the short title, resulting in its website rankings in the Alexa abnormal changes" " The pursuit of short-term reputation of cheating directly led to the Chinese Internet impetuous atmosphere. (The above comes from the first financial

Label: SP data BS server technology nbsp browser client cannotSynchronization refers to the communication mode in which the sender sends a packet only after the receiver sends a response.Asynchronous means that the sender sends the next packet instead of sending the response from the receiver.For example: Normal B/S mode (synchronous) Ajax technology (asynchronous)Synchronization: submit a request, wait for

Socket interface after connect ()There's one thing I've never understood, how does the UDP socket interface after connect do the test of sending data successfully or not? Direct sendto cannot be detected, why can I write after connect?After the UDP Connect kernel logs the destination IP and PORT in your connect, you can read and call write while the kernel will tell you the asynchronous error of the connected socketLike what:Once an error is sent to

server software to do, and then proxy server to play the client request to complete, and then return the results to the client. Proxy server to analyze the contents of the packet, figure out what to do, and then as their own identity to "proxy" to complete the request, and send the results back to the client.such as HTTP, parse out the direction of the request, and then the identity of the proxy host, the

important implications for the next steps. Not only does it affect the results you get, it also drastically reduces your workload. The right optimization development environment can provide you with excellent compiler tools, off-the-shelf optimization libraries, debugging tools, and performance evaluation tools to help you see exactly what your code is doing at runtime. Check out the webinar in the intel®

This article reprinted address: http://cenalulu.github.io/python/gil-in-python/What's Gil?The first thing to be clear is GIL not the Python feature, which is a concept introduced when implementing the Python parser (CPython). Just like C + + is a set of language (syntax) standards, but can be compiled into executable code with different compilers. Well-known comp

is not known, so the ARP broadcast packet is sent first, and in line fourth, 192.168.0.10 responds to 192.168.0.226 's request and tells 192.168.0.226 that its MAC address is 0 : 60:8:92:e2:d.In line five, 192.168.0.226 initiates a SYN request to 192.168.0.10, but in line sixth we can see that because the target host

less than the nominal capacity, which in addition to some small amount of loss (algorithm, particle difference), some phones will also be the GPU occupied a portion of RAM, so some 2G mobile phones will see the actual capacity is 1.7g~1.8g. And the usable capacity will be less than the actual capacity, is due to the system occupation and the background of the use of the reason, the general 2G mobile phone

Recently, many people are asking what the vswitch, hub, and router are, what are their functions, and what are their differences. I will give some simple answers to these questions. First, the hub, that is, the hub. Its function can be simply understood as connecting some machines to form a LAN. The switch (also known

IP address Structure To understand what a subnet mask is, you must understand the composition of IP addresses. The Internet is composed of many small networks, each of which has many hosts, thus forming a hierarchical structure. When designing an IP address, considering the hierarchical features of Address Allocation, each IP address

Service (SMS), unstructured ancillary business data (USSD), Circuit switched cellular mobile data (DSD), cellular mobile Digital Packet data (CDPD), and Universal Packet Radio Service (GPRS). Since WAP is based on an upgradeable tiered structure, each tier can evolve independently of other tiers. This allows the introduction of other bearer services or the use o

Ask for php, a socket expert, and check what type of data format I sent in hexadecimal format, however, when we get to the packet capture tool, we don't know what kind of data format he translated into. in the shadow shown in the figure, we can find php and socket experts in hexadecimal notation, see what type of data

network, and the forward proxy or packet filtering method is used to deny other external access and provide internal network access to the external network. This way, you can combine these approaches to provide the best secure access.Why is it called reverse:But that doesn't explain why he's called reverse, in principle. The proxy server handles the request from

What is the role of a router? What is the difference between it and switches and bridges? A: One role of a router is to connect different networks, and the other is to select an information transmission line. Selecting smooth and

(as a character read) in the list2, fixed format: Record data, data type, data length fixed.3, variable format: Each record has at least one variable Long data field, and a record can be a sequential string.The demarcation of the data segment (e.g., name, age) as "," as a field;Brackets, etc.4. Loader can use the physical records of multiple contiguous fields to compose a logical record that records file run status files: including the following:1. Running Date: Software version number2, all in

What is h264 video file format? H.264 is the latest format defined by the MPEG-4 standard, and it is also one of the most technically available video coding formats, representing the latest technology, some also called AVC (Advanced Video coding), a video compression standard. is