Is DNS server And Host file Are different? - dns

I am unsure Whether both DNS server and Host file are the same or different.
I Hosted an application in IIS and created A host name as website1.domain.com and tried to browse it and it didn't work.
When searching on net i found that we need to make entry in DNS server or Host file.
As in most of the sites that I saw mentioned DNS server or host file. I am unsure Whether the both are same or they both are different.

A hosts file is used by Operating Systems to manually specify the IP addresses for specific domains/subdomains - think of it as an override.
DNS however is a server - think of it as a registry - that keeps track of records pertaining to domains, such as A records, MX records etc.
For the purposes of a local test site, an entry in your hosts file would be sufficient, however for a live site, a DNS entry relating to the domain you wish to have your site hosted on would be required.
Choosing which to use comes down to a few things. Does the server upon which your hosting the site use its own DNS server, i.e. a DNS server on the same network, which the connections to the server will be using as well? Does the domain name the site uses have its nameserver set to one that is externally available (i.e. 123-reg.co.uk). If either of these cases are true, you could probably use a DNS server.
If not, is the server hosting the site running on the same machine as the client that will be viewing the site? If so, you can probably use a hosts file, pointing your domains to the localhost IP of 127.0.0.1, ensuring the domains match the bindings in IIS.

Dns server is a server that will help to resolve dns names. ie when you type google.com in your browser , the name will be passed to the dns server provided by your isp. then it will be resolved to ip address by the dns server and your request will be routed to the google ip address by isp network. host file is different one. if you add www.mydomian.com entry in your host file and map it to an ip address 192.168.0.1 then your computer will check ion your host file when you type www.mydomain.com, whether there is any entry for mydomain.com in your host file, and if exists it will be routed to that ip address. in case if there is dns server and you set that server ip in your hnetwork configuration in your pc, then all the domain name request will be sent to that dns server(if there is no host entry exists)

Related

iis manager binding vs host dns file?

In the first place i should say that it might seem a bit weird but its a challenge to distinguish between the level of these configurations,for example ,say i want my localhost be accessible through abc.com, i know i should go through two steps:
1.use iis manager bindings
2.add abc.com to dns host file
127.0.0.1 abc.com
But is not clear for me level of these configs and what is each part's responsibility ?
In a complete url request, steps as follows
User request abc.com.
DNS is request for abc.com.(That is why add abc.com to dns host file)
IP address for abc.com is returned.
Browser send request to the IP address.
IIS in server return site’s page.(That is why use iis manager bindings)
Complete request
Why to use host file

Domain not attached to the Cpanel

I registered domain on the WHM and create a new user cpanel with the domain, the domain is added to the cpanel. But when i try to browse the domain name it getting server DNS address could not be found.i updated the name servers with my server name, but nothing changed.
when i try to go through myip/~newuser it going fine to the site file, but with the domain name it's not.
You have a DNS issue in this case. Please check your DNS zone with a tool like intoDns:
https://intodns.com/yourdomain.tld
See if you get any errors there. If you do, then you have issues with your DNS configuration. Be sure that you have create the parent DNS servers for your domain if you want to use the DNS from WHM (the parent DNS servers should point to your WHM server ip).
Try using external services to query your DNS server to see if it actually works (like MXToolBox etc). Or you can use nslookup or dig right from your WHM server by connecting via ssh.

Why can't I use a port with my website domain name?

I have a registered domain name, www.aaaDomain.com, assigned to ip address xx.xx.xx.xx . I set up my site on IIS8 to use the ip address xx.xx.xx.xx and port 8020 for my website. I can connect to the website when I type xx.xx.xx.xx:8020 in a browser but I cannot connect to the website when I use www.aaaDomain.com:8020
Also, I have another website on this same server as my Default website. When I type just the domain name without the port number, my default website comes up (because DNS does not allow adding port numbers) just like when I type in the ip address without the port number.
What am I doing wrong?
Here is what my site binding looks like on IIS8.
As you already have an existing site running on the server you should check your security settings on both the Windows firewall and any other security/firewall settings you have - It sounds like you have not opened the additional port which you have just configured in IIS.
Check to see if you can ping the new site by its domain name - that will verify that you have the correct DNS setup, you can also try & browse to it via the server console (or remote desktop) if that works then its security setting somewhere blocking your access. Even if the ping request times out it should still resolve the name to an IP address for you to check. You may find that ICMP is also blocked.
If you just changed your dns record, be aware that you should wait up to 72 hours for the dns to replicate after changing your dns record.

Sub-domain hosting on a different server

I have a domain with wildcard - *.mysite.com hosted on Server1
I am planning to host a sub-domain - sales.mysite.com on Server2.
Is this achievable? If yes I have a couple of questions on this.
How does DNS know to which server to point when sales.mysite.com is requested?
Does all traffic come to the Server1 and then redirected to Server2 if the destination calls for sales.mysite.com?
this is very easy to achieve. you need to configure your dns server that subdomain.mydomain.com points to server 1 and subdomain2.mydomain.com points to server 2. the traffic won't be routed via server 1. it will directly go to server 2. thats how DNS works. In the DNS server for each domain an ip address is stored. you just need to specify your 2 ip addresses the correct way for the subdomains and it should work. more infos you can get from wikipedia http://en.wikipedia.org/wiki/Domain_Name_System

Is it normal for a DNS server to not respond until the name servers are switched on the whois record?

I have someone telling me that DNS servers only start responding after the whois record is updated to point at their DNS servers. Is this normal behaviour? Or should a DNS server respond before the whois record is updated?
Also, once the domain is active, (so either after the domain is added or after the whois record is update, depending on the answer to the above question) how long till the name servers should start responding?
I'm not referring to the time that it takes to propagate acorss the internet, but just the time on the name server for the domain. I am also not concerned with when the rest of the internet sees the change, only wondering when that DNS server should respond when using a command such as:
nslookup www.example.com ns1.dnsserver.com
For the DNS servers to be found what you call the whois record must know where to find them.
Stricly speaking, the whois record contains much more than just the DNS servers for a domain, but let's not nitpick.
Say your DesktopA needs to connect to example.com, the following servers will be contacted, assuming the answer wasn't already cached by your ISP's DNS or the local machine.
DesktopA has DNS settings pointing to the ISP, so DektopA will ask the ISP's DNS servers if they know where example.com. is located (its IP).
ISP DNS server doesn't know, so it will contact the root domain database for com. (all Fully Qualified Domain Names end in a ., even though we generally don't use it explicitly, but you can try insert it in web requests, it should work fine).
This bootstrap list of global root servers is usually updated by the OS regularly.
The root servers will know which Top Level Domain TLD server to contact for each global domain such as .com, .org, .uk, etc.
In our example, the ISP will ask the root which server to query for com domains.
The root server answers with the IP address of one of the the .COM TLD servers.
The ISP DNS server will now contact the .COM TLD server and ask it where to find EXAMPLE.
The .COM database record for example.com will contain the 2 (or more) DNS servers registered along with the domain name example.com. These are part of your whois record.
The ISP now has the IP addresses of the DNS servers for example.com as setup in the whois. It will query the first one (or the second one if the first isn't available) and ask it: what's the IP of 'example.com'?
The DNS server for example.com will look in its records and return the A record defined for the example.com domain as IP 1.2.3.4 for instance.
Your ISP's DNS server will cache this information for a predetermined amount of time (TTL) and return the IP 1.2.3.4 to DesktopA.
Desktop A can now contact the server for example.com directly by its IP.
DesktopA may cache this information for a little while for fast lookup.
Tis would be the same for subdomains such as www.example.com or john.people.example.com. Everything before the domain example.com must be declared in your DNS server so when someone query for their address, your DNS server for example.com can look up the definitions and answer them (it could very well pass them on to another server as well if necessary).
In conclusion
So, to go back to your question, your whois record must be set with the proper DNS records for your domain before anyone can access them using that domain name.
DNS Servers operate completely separate from the Whois server. The relation of how fast DNS is updated after Whois depends completely on the registrar. A registrar or web host may update DNS within a second or 2 of a customer making a change in the control panel, or it may take minutes or hours if they make updates in batch mode.
Ideally all DNS changes that a customer request should happen very quickly on the DNS server (within a few seconds), but as you note, there may be a delay until changes propagate across the internet.

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