Website optimization technology is always evolving. Today I re-read the previous front-end optimization notes and found that the section on YSlow Optimization 34 guidelines on reducing DNS lookups (reduce DNS lookups) should probably be revised.
DNS as the foundation of the Internet Protocol, the speed of its resolution seems easy to be overlooked by site optimiz
Most of the network traffic is based on TCP/IP, while TCP/IP traffic is based on IP address, but in the real network access who is willing to use IP address, because the IP address we remember inconvenient. To solve this problem, DNS is available.
DNS: Domain Name System users access to the Internet through the input www.luwenju.com actually entered a computer name, the user's computer to the
Originally transferred from http://hi.baidu.com/shyoung/blog/item/b0ccff03fd462481d43f7c5a.html
The complete DNS System of the DNS component consists of the DNS server, region, Parser (DNS client), and resource records, and you need to correctly configure them. The DNS proto
DNS and BandDNS: Domain Name SystemWorking at the application layer, it is a protocol that listens to UDP and TCP ports 53 at the same time.UDP response query requestTCP response/Etc/HostAt the beginning, there was a relationship between the name you wanted to access and the corresponding name.However, as the network grows, the management and maintenance of host files becomes very troublesome.At this time,The international IP address assignment agency
I have understood this attack for a long time and do not understand what it means to "rebind. After A little understanding, I found that the attack principle is literal. Refresh the DNS A record and bind it to another address.
In the following section, I reference the note of a fairy
"To mount a DNS rebinding attack, the attacker need onlyRegister a domain name, such as attacker.com, and attractWeb tra defa
DNS is currently one of the most indispensable servers on the Internet, and every day we surf the web with the help of DNS. The DNS server can resolve the domain name for us, locate the e-mail server, and locate the domain controller in the domain ... In the face of such an important server role, we need to do some in-depth research, this article tries to explore
1. view the Host IP address resolved by the DNS host name
Host CommandPurposeResolve a host name to an Internet address or an Internet address to a host name.SyntaxHost [-n [-a] [-c Class] [-d] [-r] [-t Type] [-v] [-w] [-z] Hostname | Address [Server]Hostnew [-a] [-c Class] [-d] [-r] [-t Type] [-v] [-w] [-z] Hostname | Address [Server]DescriptionThe/usr/bin/host command returns the Internet Address of a host (when the Hostname parameter is specified)
# # # #三-Master DNS DNS Encryption # # # #1. Configuration of master-slave DNS1) Configure two DNS servers.2) where the DNS server is configured as follows:Vim/etc/named.rfc1912.zones---------------------------------------Zone "Westos.com" in {Slave type;Masters {172.25.254.100;};The file "Slaves/westos.com.zone";allow
Today when looking at the source code of a website found rel= "dns-prefetch" href= "//static.tuweia.cn/" > A little curious about dns-prefetch, Because more than once to see, today finally can't help to see what he is what technology? Here is a brief description of Dns-prefetch found on the internet.DNS implements domain-to-IP mapping. Through the domain name to
Before you build a DNS server, introduce the terminology in several DNS
1, forward lookup zone: mapping for Computer name to IP address. When a DNS client initiates a request to a DNS server to resolve the IP address of a computer name, the DNS server looks in the forward l
In the previous blog, we introduced the architecture of DNS, the common records, also introduced the configuration of the secondary server, today we will introduce some of the files behind the DNS server. In fact, the work of the DNS server relies on these files, understand the background files of DNS, to better unders
Problem phenomenon:AD The domain controller operating system is WIN2008R2, and a rejected error occurs when a DNS host (A) or alias (CNAME) record is manually added in DNS Manager. However, after you join the client to the domain, you can see the DNS host (A) record for the corresponding client in DNS Manager. In the s
Configure the DNS service in Liunx and the DNS service in Liunx
When you Ping the host name, you can map the IP address of the host, and vice versa. Configure and specify the DNS server to quickly deploy the cluster. You do not need to modify the HOSTS file on each host to resolve the IP address and host name. In Linux, DNS
Most DNS cache servers exist in small enterprises. they are not responsible for domain name resolution and are only used to help users query domain name information from other DNS servers. The queried information is saved locally to facilitate the next use of the domain name. it is valid to shorten the domain name query time and save the local information. The following is... information
Most
The previous section mentioned some of the content of the recursive query, but said very little, but also very general, this section will be based on the principle and the case two aspects of DNS recursion and iterative query.
Before that, we need to learn some background to better understand today's topic.
In the Internet, a smooth resolution of a domain name is inseparable from two types of domain name servers, only by the two types of domain name
Originally in this verse to explain the installation of DNS, but I found that in fact before this, but also need to explain a few basic concepts, first of all, the DNS suffix.
In the previous basic chapters, we know that a domain name can be divided into the main and suffix 2 parts, where the host we can understand as a host or a network terminal name, the suffix directly determines the nature of the domai
@ Zheng yu Summary
I. symptom: Java httpclient initiates an HTTP request to the WebService interface under the x××× open. x××. com domain name from the master station data center, which is extremely slow. Troubleshooting:
1.1. wget test results No
Specify the IP protocol and the interface for wget to access it. The time is 4.163 seconds, which is basically a waste of host parsing.
If the IP protocol of the specified wget is IPv4, The wget test takes only 0.096 seconds.
1.2. WGEtCompari
Document directory
DNS structure:
Header section:
Question:
Resource Structure:
Every time we enter any domain name in the browser to access a website, we use the DNS protocol to perform a "Domain Name: IP" query. As a command line user, the NSLookup command is the most widely used DNS-related command. As a programmer, taking C # as an example, the IP add
When
NetlogonWhen the service cannot register or cancel registering multiple resource records, the System Event Log will recordNetlogon5781Error message. The event description does not contain the names of these resource records. In addition, the event description may be "no ",DNS servers are available ", note: the common cause of these errors is that the domain controller references itself as the DNS
[Daily] DNS iterative Query Process and dns query Process
DNS is an application layer protocol, and the port numbers are tcp/53 and udp/53.DNS query process, such as accessing www.test.com1. The client queries www.test.com2. query the preferred DNS server, in Linux/etc/re
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