nightfox1405241487 0 Report post Posted June 4, 2005 I don't know if this is the exact proper place, but I'll just put it here because it deals with the web! I know this may sound stupid, but how does a DNS server work? Like big huge companies like Microsoft I know has to use one to spread the website out over different servers. Like if you type in https://www.microsoft.com/de-de, your request goes through a DNS server and it directs you to the proper server, right? But now lets say I send an email to Bill. That email has to go through the DNS server to get to the mail server. I just don't get how this is done. I have done a google search for "DNS Server" and find some server packages and read the information on the site to try and understand the server. If I wanted to launch a mail server, FTP server, and web server, I could do it, but they'd be all on the same machine which can put a ton of stress on the machine. So exactly how does the DNS server know what to do? Such as the page: https://support.microsoft.com/en-us could be on a different server than the one that hosts https://www.microsoft.com/de-de. How does the DNS server know which web server to point to? Thanks if you can help me understand this! [N]F Share this post Link to post Share on other sites
signatureimage 0 Report post Posted June 5, 2005 Dear nightfox, DSN servers do NOT participate themselves in the sending of email or the browsing of the web... When you type the name of a web site in the address bar of your browser, it is your browser that will first form a TCP/IP packet for the "Address Resolution Protocol" (ARP), requesting for the translation of the server name into a TCP/IP address. (Suppose you want http://www.somewhere-paris.com/en/ and you connect from yourisp.jp) These ARP packets will be routed in the following way: - on your own machine: the ARP cache that has been constructed since power-on - on your own machine: the hosts file + result: NOT FOUND - on the DNS server (yourisp.jp) of your Internet service provider (ISP): the ARP cache - on the DNS server of your ISP: the configuration file + result: NOT FOUND - on the DNS server for domain (jp) (the last word of your ISP's domain): the ARP cache - on the DNS server for domain (jp): the configuration file + result: info NOT FOUND in domain jp - on one of the top domain DNS servers: tha ARP cache - on one of the top domain DNS servers: the configuration file + result: info IS OVER THERE: - on the DNS server for domain (info) (the last word of your destination): the ARP cache - on the DNS server for domain (info): the configuration file + result: somewhere.info IS OVER THERE: - on the DNS server (somewhere.info) of your destination: the ARP cache - on the DNS server (somewhere.info) of your destination: the configuration file + result: http://www.somewhere-paris.com/en/ IS OVER HERE, AND HERE IS ITS TCP/IP ADDRESS The same is true for your e-mail client and your FTP client. They all have to first translate a server name into a TCP/IP address by means of the Address Resolution Protocol (ARP). You can inspect your local ARP cache with the ARP command-line utility of your OS. Once your browser has obtained the TCP/IP address of the web server, your browser will form a TCP/IP packet for the "HyperText Transfer Protocol" (HTTP), using the TCP/IP address that has been obtained. Similar action is true for your e-mail and FTP clients. The File Transfer Protocol (FTP) and the Simple Mail Transfer Protocol (SMTP) all work only with TCP/IP addresses, not with names. The DSN servers no longer participate in these TCP/IP packets. So, search the Internet for more explanations of the ARP.... Share this post Link to post Share on other sites
Rudy1405241475 0 Report post Posted June 5, 2005 Quite an impressive job Signatureimage but I see you left the explanation of a DNS for me.DNS stands for Domain Name Server and really is associated with DOMAINS. But of course without dns servers there will be no internet. Let me see if I can explain this in layman term.Now think of the internet as a village and a village is made up of family’s right? Each family member has an address, let’s say an IP address that corresponds to each individual name. For example Sam’s ip address is 10.1.1.1, and Jim’s ip address is 10.1.1.2.If a neighbor down the road wants to send a message to Sam they will send a message requesting permission to talk to Sam. The head of the household who handles the list of names and ip address (dns database) looks to see what Sam’s ip address is and grant permission.The reason for having this type of system is Sam’s ip address can be changed without changing his name. So if a message is sent to Sam no matter what his ip address is, will get to him because a dns tracks the changes of ip addresses in its domain.Also an internet address (external address) is not the same as a local address (internal address). A dns keeps track of all the addressing and name association. With thousands of ip addresses being changed every minute all over the world without the trusty old DNS the internet would keel over and die.Was that simple enough for you to understand? I know you did, may the force be with you. Share this post Link to post Share on other sites
Nqon 0 Report post Posted June 5, 2005 Simple is always the best way. DNS Server transform a domain name (like http://forums.xisto.com/) to an ip (203.123.12.44). This is since your computer cant find out where things are hosting using a name, you need those numbers (ip). Share this post Link to post Share on other sites
whistle 0 Report post Posted July 19, 2005 You can assign the dns server of your domain to a dns hosting site and then try to configure it. There must be some useful information to help you. Besides you can pratice on your own, because to built up a domain name server is much harder to use it. Share this post Link to post Share on other sites
Hercco 0 Report post Posted July 19, 2005 When you mentioned big sites (like microsoft.com) spreading the traffic to different servers, you are right, but like guys kind of pointed out it has nothing to do with DNS. DNS just translates the literal address to whenever the entry point to the microsoft's network of webserver is (an IP address), Then, the first server receiving the traffic does what you talked about, distributes the traffic between different servers, to balance load.It is infact rather interesting topic. While it may sound rather trivial task to do, it actually has lot of different ways to do it, and none perfect. The type of traffic defines what method is the best and because of this predicting and monitoring traffic is extremely imporatant if your looking for getting the best out of your servers (and who wouldn't).A typical, and most obvious way to do it is by handing the first task (a http request for example) to server 1. When the next task arrives we check if server 1 is busy, if so, give th task to server 2 and so on until you run out of servers and you have to start queuing the tasks. This works and is in use with many big services. However, an alternative method can prove to be highly more effective...How it works is that it has a certain time limit for a server. A time limit that its tasks (combined) may not ever go over. The system starts bu queuing all tasks to server 1. If it turns out that it cannot do it withing the time limit, the task is cancelled and started from scratch at server 2. If it cannot be done there, then start from scratch with server 3 and so on.It sounds like a real bad idea. You're doing lot of processing in vain.. But what the idea is that it doesn't make short processes (requests) to wait for the long ones to visit. With the conventional system you can easily have all servers running a long process, and short processes taking only fraction of the time that the longer ones would would have to wait. With the latter system, you'd pretty much always have server one reserved for short processes. Ain't traffic engineering fantastic Share this post Link to post Share on other sites
Casanova1405241497 0 Report post Posted October 4, 2005 While most of this topic doesn't require much technical knowledge, there is one technical part of DNS you should understand in order to grasp the political issues.When you type a name, like "eff.org" into an internet program, it needs to find a way to map that to the internal routing number the internet really uses to reach the EFF computers. We at the EFF want you to be able to reach us using that name, too.To do that, your computer uses DNS like a database. DNS translates from a name like "eff.org" into a raw number called an IP address. All internet traffic requires these numbers to work. Some computers do your DNS directly, but with most personal computers, your PC asks another computer at your ISP or corporation to do the work. The important point is that the looking up of the name is normally done by a computer you or your site controls, or one you pay to do such work for you. That computer has a list that was installed in it by the people who run it. In almost all cases, that list just came with the DNS software, because everybody in the world uses a similar list. It's a list of what are known as the "root" servers of DNS. These are the master servers that can help you look up (resolve) any name you want to ask about.There are about a score of these root servers around the world, and they all copy their own data from one master server, which is under the control of ICANN. Each one has the same data inside. The root servers don't actually contain much. They mostly list where you will find the servers that can look up names in the "top level domains" like .com, .org, .us, .uk etc.Once the root server tells your system where the master ".org" server is, your system asks it where "eff.org" is. In particular, it gets back the raw internet IP address, the low level "phone number" of the internet. With that answer, your computer can talk directly to the computers at eff.org(Quite often this is more efficient than it sounds because all the computers along the path remember the answers to questions they have asked recently, and don't need to ask them again.)The important thing to know from all this is that while ICANN controls the master root server, and the other root servers are copies (mirrors) of it, and almost everybody uses the same list of root servers, there is no law that makes this so. A few people can, and do, use other lists of root servers. In theory, if enough people got upset at ICANN and the root servers, they could switch to another set, and that other set could look up names for you any other way you might choose.In practice, such a switch would be very hard to do, especially a switch that changed who the master for ".com" was from Network Solutions to come other company. If people switched, some people might get a different answer for whoever.com than others do. You couldn't hand out a domain name on your business card and expect it to work reliably for all the people you give it to.So while there is no actual legal power in ICANN, there is a natural monopoly for the "root" (master) of the domain system, because if everybody doesn't use the same list, we lose some valuable features Share this post Link to post Share on other sites
