reverse dns ip lookup

First, reverse zone: The domain name is resolved to IP====================================================================================Note Close Iptables,selinuxOne, DNS server R reverse resolution required environment1. Three machines are needed. First: 192.168.137.140 do

After the MySQL database receives a network connection, it first obtains the IP address of the other party, and then performs reverse DNS resolution on the IP address to obtain the host name corresponding to the IP address. Use the host name in the permission system for perm

Let's say your server IP is 211.147.9.106 1 First, you should know which DNS server is responsible for this IP's reverse domain name resolution. You can use this page to query reverse domain name resolution information http://www.dnsstuff.com/tools/ptr.ch?ip=211.147.9.106

This morning the bean accidentally found that the company's DNS server above only the forward parsing, and there is no corresponding PTR record. In other words, the IP address can be resolved by the domain name, but the reverse IP address is not able to find the domain name.1 hours wrote a very simple script, to determ

domain configuration file for 192.168.1.rev [Root @ server etc] # cd/var/named/chroot/var/named // enter the/var/named/chroot/var/named/Directory [Root @ localhost named] # cp named. local 192.168.1.rev // Copy the domain configuration file 192.168.1.rev [Root @ localhost named] # vim 192.168.1.rev -------------------------------------------------------------------- $ TTL 86400 @ In soa localhost. root. localhost .( 1997022700; Serial 28800; Refresh 14400; Retry 3600000; Expire 86400); Minimum

By default, mysql will automatically reverse parse. If we cannot handle the problem, we will find a large number of unauthenticated user prompts when viewing show processlist, the following describes how to solve unauthenticated user. Example The Code is as follows: Copy code Mysql> show processlist;| 20681949 | unauthenticated user | A. B .C.D: 52497 | NULL | Connect | Reading from net | NULL || 20681948 | unauthenticated user

little about the data structure can realize that reverse queries are performed in the forward query domain. The only way to do this is to traverse the entire data set-for DNS, that is, traverse the entire database, this will bring a huge burden, so DNS adopts another method, using another subtree to maintain the corresponding table of

; Refresh14400; Retry3600000; Expire86400); MinimumIn ns localhost.2 in ptr www.linuxidc.com. // Modify the last line to (my IP address is 192.168.1.2 and the domain name is www.linuxidc.com)--------------------------------------------------------------------[Root @ server named] # bind-chroot-admin-s // automatically sets the group and permissions (/usr/bin/find may be prompted in CentOS: /var/log/named. log: the file or directory does not exist)[Roo

1. This article uses the system comes with the RPM package to install, because this Linux system is optimized, therefore does not need the CD-ROM to mount.2. IntroductionBind is an open source DNS server software developed and maintained by the University of California, Berkeley, with full name Berkeley Internet name Domain It is currently the most widely used DNS server Software in the world, supports a va

Cases The code is as follows Copy Code Mysql>show processlist;| 20681949 | Unauthenticated user | a.b.c.d:52497 | NULL | Connect | | Reading from net | NULL || 20681948 | Unauthenticated user | w.x.y.z:52495 | NULL | Connect | | Reading from net | NULL | Found that there are a lot of unauthenticated users trying to do login using MySQL, and when this happens indefinitely it can cause the system to be very slow. Access to the MySQL official website that thi

instead of the IP address. Why don't we use IP addresses for access? Because the IP address is a group of pure numbers, it is hard to remember. For example, the IP address of geek college is 121.42.104.52, and the domain name is www.itcen.cn. If we use an IP address to acce

into the field, located in the application layer. (2) What is the role of DNS? It is the parsing service that provides the domain name to the IP address. We usually visit a Web site, often using a hostname or domain name to access, rather than directly through the IP address. Why don't we use an IP address to access i

BackgroundUser A Domino mail server was hung up and a new one was built, resulting in a pile of back letters. Here are two of these questionsQuestion one:No route found to domain xxx.com from server xxx/xxx. Check DNS configuration."Issue Tracking"1. Server Side--run--cmd2. nslookup3. Set TYPE=MX4. Enter xxx.com to discover that this domain name is not resolved at all.DNS configuration address problem was found, changed the

Name System) is a core service of the Internet, a distributed hierarchical system that maps domain names and IP addresses to each other. DNS implements a hierarchical domain name space by allowing a domain name server to delegate a subset of its domain name resolution services to a child server.　　DNS consists of the parser (Resolver) and the domain name server t

DNS forward resolution resolves the domain name to an IP address, and vice versa.650) this.width=650; "src=" Http://s2.51cto.com/wyfs02/M01/8B/47/wKioL1hI_ArAbriIAAC9cgOf9lg567.png "title=" 1.png " Style= "Float:none;" alt= "Wkiol1hi_arabriiaac9cgof9lg567.png"/>650) this.width=650; src= http://s2.51cto.com/ Wyfs02/m02/8b/4b/wkiom1hi_aqij7oeaaeppcnc8la228.png "style=" Float:none; "title=" 1 (2). png "alt=" w

"Netcom download". This is an application for Multi-Point deployment. Can I automatically connect requests to the fastest service without the user's choice? The answer is that some application services can be implemented. Some equipment manufacturers have produced some hardware products for this demand, such as F5 GTM. In the DNS field, IP Anycast + BGP is used for Multi-Point deployment.

Domain Name Systems Dns:domain Name System A distributed network directory service, which is mainly used for the mutual conversion between domain name and IP address. Use UDP protocol 35 ports for communication. How to work: in order to map a domain name to an IP address, the application invokes a program called a parser that transmits the domain name as a parameter to the program, and the parser encapsulat

1. The public port of DNS protocol is 53, which is commonly used for UDP encapsulation (TCP encapsulation can also be used ). DNS (Domain Name System) is a distributed database (IP-name) 2. concepts: (1) The DNS domain name can contain a maximum of 63 characters, regardless of case. For example, top-level (level-1) do

That, since the domestic technology has appeared the DNS pollution problem, often caused a lot of foreign site access is not normal, so by reference to some blog to avoid DNS pollution method, decided to build an Ubuntu JeOS DNS cache server, the server uses TCP to obtain IP resolution, This avoids the problem of

IP Reverse Lookup domain name, now used is generally Bing's an IP query function, that is ip:222.222.222.222 The PHP code becomes Calling methods $result =getresult ("124.205.228.114"); Print_r ($result); function GetContent ($url) { $content =file_get_contents ($ur