So I am setting up my at home server, and I am setting up my static ip address. I noticed that I need to input my ISP's DNS servers. Why? It does not seem to list a DNS server for DHCP. If I truly have a static ip address (which RCN, my ISP, claims that I have), then why do I need a DNS? What is being resolved at the DNS? Thank you in advance.
As you said you need DNS server/s to resolve hostnames to IP addresses. If you do not use a DNS server your PC/router wouldn't know what's the IP of the sites you want to visit (unless you hardcode all the addresses, of course). This are resolving/recursive DNS servers, not authoritative DNS servers.
When you do not use DHCP these servers are not automatically obtained, that is why you need to manually put them.
Related
I'm a little confused about IP addresses.
I know that every web domain has an ip address.
Does the IP address represent the physical machine / host the website files are stored on?
Therefore when DNS lookup is performed, the domain's IP address is returned to the client. The client then uses this ip to contact the server that the web files reside on.
Is my understanding correct?
Many thanks
You are correct.
It is kind of like how some companies may say Dial PIZZAHUT instead of saying, Dial 74992488. PIZZAHUT is easier to remember, but you actually are dialling the number.
You're talking about HTTP protocol. Yes, FQDN (web domain) is resolved to IP address by DNS server. Client will connect to server IP address. Since you're probably using HTTP 1.1, HTTP request will contain also FQDN. This information is used by web server to perform several checks, like SSL certificate validation or Virtualhost management (several domains on a single IP address).
I have got one firewall, with a public IP (dynamic) provided by my ISP.
As the IP is dynamic, I registered a domain in the service NO-IP as not to worry whether the IP changes anymore.
The problem:
Looks like my ISP is also giving a name for that IP, so when I resolve it (standard DNS configured, such 8.8.8.8) it would resolve the name in favour of my ISP.
The key point:
¿Is there any way to "OVERRIDE" the name given by the ISP with the one registered in NO-IP, in order to ALWAYS resolve to the no-ip name?
Thanks!
Whatever you did with NO-IP/DDNS, it will have no effect on Reverse DNS lookup. Reverse DNS is controlled by whoever "owns" the IP address, usually your ISP, so they would have to change the record according to your request (or sub-delegate it to your DNS servers) which they will almost certainly not do since you have dynamic IP address.
I've been trying to port forward on my router for the last couple days with little success. I just realized that my IP is not in fact static as it is supposed to be, would this cause ports to show as closed?
Not of course.
You can open ports on your firewall.
The problem is that your ip will change and someone to find you again needs the new one. Find your new one there http://whatismyipaddress.com/
You can work with a dns manager like http://www.noip.com/ to have a dns name.
Also the problem with the firewall ports is that your computer will change your IPV4 address and then you must edit your port configs again. Go to run->cmd->write ipconfig and see that your ip is different now.
No, if you setup port forwarding, it will work regardless of what your external IP address is and will remain in place even if your external IP address changes. In other words, traffic will be forwarded to the internal IP address on port you specify, even if the external IP address changes.
Now, the trick is going to be finding out your external IP address when you are working remotely. This is one creative way:
http://lifehacker.com/5737187/use-dropbox-to-find-the-ip-address-of-your-remote-computers
If you're having other issues, try looking into the firewall settings of your computer.
I wonder if is it ok to host multiple sites on a server with one IP address?
I bought server on hetzner and I want to host 10 different websites of my clients. Eg. client1.com, client2.net, client3.org etc. I changed "A record" in all domains on IP address of my server. Is there any reasons to not do that? Or maybe I should buy additional IP address for each site?
Thank You.
Sure it is, your webserver will be able to filter requests to the correct site based on the incoming request's URL.
In Apache this is done by adding a new virtual host to your configuration.
So if I try to navigate to google.com and I don't have the ip address cached, my browser will attempt to contact google's nameservers. If the nameserver is ns1.google.com, how exactly is the nameserver's ip address resolved?
Your browser doesn't contact Google's nameservers directly (unless you work there), instead it attempts to contact your organization's DNS servers (as defined by your ISP or network admins) to resolve google.com, and those DNS servers work from there, working their way up the DNS hierarchy to the DNS root servers if necessary.
How do the DNS root servers know the IP addresses for Google's servers? They don't. They look at the ".com" in the domain name, and forward the request to the ".com" TLD servers, currently managed by Verisign. Verisign notes the ".google" part of the domain name, and forwards the request to Google's DNS servers.
How does Verisign know the IP address of Google's DNS servers? Google tells them by registering resource DNS records with them when the IP address changes.
Of course, caching is used up and down all levels of this tree.
See http://www.howstuffworks.com/dns.htm for more info.