what is dns cache

Accidentally saw an article about Nodejs sending an HTTP request does not cache DNS results. This means that if you write an HTTP capture program based on Nodejs, not providing DNS caching will allow each request to be silly repeatedly resolved

Front-end page optimizationWhere did the time go? Only 10%-20% of the end-user response time is spent downloading HTML documents, while the remaining 80%-90% time is spent on the relevant components of the download page. such as: pictures, flash

Imagine using a browser to open the Imooc.com website, HTTP traversed the link:1. First, it is the imooc.com domain name resolution,(1.1) The browser searches the DNS cache of the browser itself. （DNS (domain Name System), a distributed database

Chenxi's html Study Notes and chenxi Study Notes 1. browser kernel:1. ie: trident Kernel2. firefox: gecko (gecko) Kernel3. safari: webkit (Browser core) Kernel4. opera: It used to be the presto (Rapid) kernel. Now it is switched to Google's blink

I. Introduction of the AgreementHTTP (Hypertext Transfer Protocol, Hypertext Transfer Protocol) is a set of computers to communicate through the network rules, so that the HTTP client can request from the HTTP server to the information and services,

In the process of accessing the Web site, we may often encounter the phenomenon of inaccessible web pages, when encountered this phenomenon, I believe most people will subconsciously think that the network dropped, or the target site of the server

In the process of locating a domain name through DNS, it is possible to pass through several intermediate DNS servers to find the specified domain name, so locating the domain name on the DNS server is a very expensive operation. In Java, DNS

Install dnsmasq In Ubuntu. Run the following command: sudoapt-getinstalldnsmasq to edit the configuration file of dnsmasq: sudogedit/etc/dnsmasq. conf: # resolv-file = replace it with the following statement: resolv-file =/etc/resolv. dnsmasq. conf

one. DNS (Domain Name System, DNS), the Internet as the domain name and IP Address one of the mutual mappings Distributed Database To make it easier for users to access Internet , instead of remembering the number of IP strings that can be read

When we access network resources through a domain name, such as opening a webpage or using the FTP service, the system needs to request the IP address pointed to by the domain name from the DNS server. By default, the Windows system caches the

Recently, the local DNS of foreign servers is always faulty. Transient disconnections will affect services. So I found two servers in the data center and installed keepalived and dnsmasq on the local DNS cache.The installation process is relatively

1, click on the lower right corner of the network connection, select the status to see whether the current network connection is normal. (whether there is a small exclamation mark) 2, if the network connection is normal, press win+r key, open run,

Currently the latest version is 2.7.1, can go to its FTP download: http://www.thekelleys.org.uk/dnsmasq/ The installation process is relatively simple Yum-y Install dnsmasq* wget

In actual application, DNS resolution errors may occur, that is, when we access a domain name, it cannot be resolved to an IP address, however, you can directly enter the website IP address for normal access, which is caused by a DNS resolution

One, the problem of network setup This causes more than the need to manually specify IP, gateway, DNS server networking, and use proxy server to surf the Internet. Double-check your computer's network settings. Second, the problem of DNS server When

The principle and process of DNS parsing.When a user visits a webpage on our site, he needs to go through the following steps:1) Find the storage server for this webpage;2) The server will access the user's request information;3) The server locates

First, understand what is the number of IIS connections (instant connections)The number of IIS connections refers to the number of concurrent requests in several cases: (this example uses the number of allowed instant connections) A. the user

This phenomenon has a high probability of occurrence, so this article will teach you some basic troubleshooting methods from scratch. 1. What is a DNS resolution fault? Generally, the addresses www.jb51.net and www.kanshule.com we access are

The DNS resolution process is both important and difficult. I will explain it step by step based on my understanding. There may be errors. please correct me. In the following steps, DNS resolution is successful if the DNS cache contains the

Document directory   The customer called at last night and said that the website could not be accessed. He immediately ran up, entered the domain name, and asked my friend to enter it.Change access from IP address OK, DNS problem. I came to the