Is it possible two hostnames share the same IP address? - url

I'm confused whether is it possible that two hostnames share the same IP addresses? And why?
What about if one hostname represent more than one IP address, is it possible too? And why?
detailed explanation is really appreciated :)

I know of Apache Virtual Host, which allows webservers with different hostnames (domainnames), to be hosted on the same IP address.
The webserver sends the domainname we wants while connecting, and webserver returns the right set of pages.
Heres something more specific if you want to further look into it https://httpd.apache.org/docs/2.4/vhosts/examples.html

Related

Realmlist - IP works but domain doesn't

I'm struggling to get my AzerothCore Docker instance to allow logins via the internet when using a domain instead of an IP address. My ISP only offers dynamic IPs so I'm using dynu for simplicity.
If Realmlist set to domain in acore_auth.realmlist I can connect over LAN but external connections get stuck at realm select screen. However if I change the realmlist to just my external IP it works for both so doesn't look like a firewall issue.
The domain is working with webserver hosted on the same machine so that can't be the issue. Any ideas?
I don't know exactly the reason why this fixed it, but I tweaked some of my pfSense settings for DNS resolution (removing my domain from the overrides) to get it going. Hopefully this might be useful to someone else!

Is there a difference between ftp.mysite.com and using an IP directly?

Lets say I use DNS to configure ftp.mysite.com to my site's IP, I want to give clients the credentials to use the ftp site. Can I give them the URL (ftp.mysite.com) OR should I give then the IP directly (even though the URL points to that IP).
Am I risking compatibility issues of some sort?
Do not use an IP address, always use a domain name. A domain name is less likely to change and carries more information than an IP address.
While a domain name is indeed just an alias to an IP address, a single IP address can be used for multiple domains. This is common with virtual hostings.
In this case, an IP address may not carry enough information. This more common with HTTP, where a domain name, that is otherwise lost in domain-to-IP resolution, is provided to an HTTP server using Host: HTTP header.
FTP protocol has a similar mechanics, the HOST command. But as that command was introduced relatively recently, it is actually quite rare that an FTP server relies on this. Even on shared hostings, a domain is usually included in an FTP username to allow even FTP clients, that do not (yet) support the HOST command.
See also Do the SSH or FTP protocols tell the server to which domain I am trying to connect?
there is no deference. you can give either you IP or your domain name. once people have the domain, they can get your IP very easy.
the domain can be better choice in case the IP is going to be changed.
Most FTP servers are hosted on port 21 (or 22 for SFTP).
ftp.mysite.com usually points to localhost:21 or localhost:22
So there is no difference, except for the ports.

Is it possible to supply ip AND hostname in URL?

I'd like to give a URL to some non-tech coworkers so that they can view a proof on a webpage on our test server.
This server is not in their DNS, so I'd like to supply them the IP, but there are several sites running on the same IP. Is there a way to put the IP address and the hostname into a url? Else, is there another way to achieve my aim (besides asking my coworkers to alter their hosts file)?
Not that I know of. You could maybe host the site on an alternative port though? Then you could just use the ip and the port for the url.

How do I make localhost:3000 available world-wide with my IP adress?

I have a Ruby on Rails application running on localhost:3000. I would like to make it available world-wide, using x.x.x.x:3000 (my IP address).
I'm on Windows XP SP3.
Disable your firewall(s)
Ensure you have port forwarding for your computer enabled in your router (if present)
Thats all! ;)
The key is to run it on the internet facing network adaptor, which might already be doing. You then need to to set up port forwarding on your ADSL or cable modem, if you are behind one (or a similar NAT device). Finally, get a friend to attempt to connect to you.
You might want to use a DNS service to alias your IP address, so people don't have to type it in by hand.
If you specifically need "localhost:3000", then go for #Joe answer, but if you do not care about the URL, you can use https://ngrok.com/.
Simply download it, then run ngrok localhost:3000 in terminal.
You would probably want to ensure that you have a static IP address to start with. You can apply to your ISP for one of these.
You then want to ensure that you have adequate security in place...there are tons of books etc about hardening your server.
If you have a static IP address, you'll need to turn off your firewall and you should be able to reach your machine. (Turning off your firewall isn't really a good idea, but that's a different question.)
If you have a dynamic IP address (you probably do if you're not sure), you need to look into something called "Dynamic DNS", as this will allow our computer to have a constant name, even if the IP address changes. Note that with all the technologies at play these days, your IP address locally is usually not the same one you see publicly. This can be a bit confusing if you're not sure what's going on.
All that being said, most people would opt for some sort of external hosting. This is much better from a security standpoint. Look at heroku for rails hosting. Their free option may be exactly what you need.
If you are running Apache on Windows, there is a button in the Apache tray icon. I can not recall the name but is something like ''go live''. And of course you have to set up the firewall or port forwarding on your router.
You answered your own question. IP addresses are unique over the internet. Just type in the x.x.x.x:3000 and you're there. If you want a human-readable address like yahoo.com, look into dyndns.com or other free domain-name services.

Method to get the client ip address

I'm developing an application where it seems likely that people will attempt to hide what their client IP address is behind a proxy server.
Is there a unified way to get what the actual client IP Address is behind the proxy? Looking at the Ruby docs, it explicitly states that
request.remote_ip
and
request.remote_addr
both would return the proxy address and not the actual client IP and I'm thrown by the "may contain" descriptions in the rest of the HTTP headers.
It depends if the proxy supports X-Forwarded-For. I'd run some tests to be sure that remote_ip isn't what you're looking for - based on a quick glance at the code it attempts to read the HTTP_X_FORWARDED_FOR header.
I'm typing this from a machine that's behind a proxy. I'm not "hiding", it's how my organisation (and most others large enough to have a server) works. I don't have a fixed IP address: it's allocated dynamically. So I can't see how knowing my "current" IP address is going to help, since it'll be different tomorrow. Heck, I may be connected via a different proxy tomorrow (I work for a large organisation)!
At home, I have several machines connected through a router. Again, I don't have a fixed IP address: it's allocated dynamically by my ISP. It's a large ISP, so there's probably a proxy server somewhere upstream.
So I think what you want is not technically possible. What kind of application would make it "likely that people will attempt to hide what their client IP address is" anyway? What problem are you trying to solve?

Resources