Difference between revisions of "How internet addressing really works"

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(Created page with "(This is a very rough draft...) There're 2 ways to get to a machine. IP address & name. But to use name, you need to have DNS set up. Either way, there's also the port. T...")
 
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When your entire network is on a single address as far as the outside world is concerned, you have a couple options to access individual machines.
 
When your entire network is on a single address as far as the outside world is concerned, you have a couple options to access individual machines.
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== Port Forwarding ==
  
 
You can forward specific ports to specific machines (probably with a bit of fiddling in Firewall/NAT on your pfSense box...) or you can set up proxies.
 
You can forward specific ports to specific machines (probably with a bit of fiddling in Firewall/NAT on your pfSense box...) or you can set up proxies.
  
 
Port forwarding is pretty straightforward, but you need to remember how you've set up the ports.
 
Port forwarding is pretty straightforward, but you need to remember how you've set up the ports.
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A good example of how this can work is my general habit of forwarding a port outside the range of [https://www.webopedia.com/quick_ref/portnumbers.asp Well-Known TCP Ports] to SSH on any of my internal machines that I may want to access while away from my own network.
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As an example, I have a machine on my network at 192.168.0.99 (Not an address accessible to the outside world) & I'd like access to it while away.  I go into Firewall/NAT on my pfSense box & forward port 52099 to this address & translate the port number to 22 (SSH).  This gives me the ability to SSH into the machine pretty much anywhere I may be as long as I have internet access.
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== Proxies ==
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Generally, when speaking of proxies, we're talking about web browser access.
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(Not always tho...  But that's a deeper discussion.)
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Web proxies are handled by your main web server.  Take a look at [[SBN - Proxy Server Notes|Proxy Server Notes]] for some useful details on how this works.

Revision as of 01:44, 17 October 2020

(This is a very rough draft...)

There're 2 ways to get to a machine.

IP address & name.

But to use name, you need to have DNS set up.

Either way, there's also the port.

The port is specific to the actual service on the machine.

i.e.: port 80 is HTTP, port 443 is HTTPS, port 22 is SSH...

When your entire network is on a single address as far as the outside world is concerned, you have a couple options to access individual machines.

Port Forwarding

You can forward specific ports to specific machines (probably with a bit of fiddling in Firewall/NAT on your pfSense box...) or you can set up proxies.

Port forwarding is pretty straightforward, but you need to remember how you've set up the ports.

A good example of how this can work is my general habit of forwarding a port outside the range of Well-Known TCP Ports to SSH on any of my internal machines that I may want to access while away from my own network.

As an example, I have a machine on my network at 192.168.0.99 (Not an address accessible to the outside world) & I'd like access to it while away. I go into Firewall/NAT on my pfSense box & forward port 52099 to this address & translate the port number to 22 (SSH). This gives me the ability to SSH into the machine pretty much anywhere I may be as long as I have internet access.

Proxies

Generally, when speaking of proxies, we're talking about web browser access.

(Not always tho... But that's a deeper discussion.)

Web proxies are handled by your main web server. Take a look at Proxy Server Notes for some useful details on how this works.