(I'm skipping IPv6, which
1- makes much more sense but
2 - also still isn't widely enough used to be an issue.
A 4 part
That's a lot!
and also
Not enough!
So we use Network Address Translation.
Where one EXTERNAL IP, can work for
MULTIPLE INTERNAL IPs
Like your router!
eg:
LAN - Local area network
WAN - Wide area network
MAN?- Metropolitan area network
<deep breath> yes. The phrase lately means two related, but often different things:
1) Virtual Private Network.
Just as it sounds. Imagine a set of networked computers, but spread out across the internet. Traffic is encrypted and tunneled so it’s as if all the computers are together in an enclosed place....
They could all access the net independently – or you could FORCE all traffic through a central location, for reasons.
..like monitoring – or
2) to OBSCURE the source for anonymity.
This is usually what is meant by that service you buy. Really, they should just call these what they are: “proxies”
Sits in the middle and does the work of ..routing.
Even though the whole house address is 200.200.200.200
"The laptop (192.168.0.4) wants google.com (142.250.64.142)"
"But the desktop (192.168.06) wants Roblox" ...etc.
This explains why the INTERNAL command and
the EXTERNAL command to get your IP address may be different.
INTERNAL: "ifconfig" or "ip link"
EXTERNAL: e.g. "curl icanhazip.com"*
Note how the second one is reaching out to an external website..
Two important concepts:
INTERNAL: Hosts file
EXTERNAL: The DNS system.
You can just make up your own. Eg
/etc/hosts.
(easy way to adblock, e.g.)
0.0.0.0 annoyingads.com
Basically, a network of "phonebooks"
This is why "hosting" and "domain names" can be different paid services.
Buying a Domain is just "controlling the name, eg. jrm4.com"
— where you just tell, e.g. namecheap, where that name should point to...
Hosting - a computer (possibly virtual) on the internet
This is what you likely want for anything that
MUST be up all the time.
I pay for this for jrm4.com
Again, this is the literal "somebody elses computer"
Ports are to IP addresses, roughly, what extensions are to telephone numbers.
Well known defaults (often not specified)
21 – FTP 6888+ - Bittorrent 22 – SSH 655 – VPN 80 – Web/HTTP 443 – Web/HTTPS BUT – you can usually redefine these 8080 – other web stuff however you want, depending. 5900 - VNC
Ifconfig vs. whatismyip.com will give you different addresses.
The LATTER is the ip address to the “world”
Use NAT / Port Forwarding to get to the “right” computer.
(Remember, your router is just another computer, it ALSO has an IP)
Usually, have entries like the following:
SERVICE NAME STARTPORT ENDPORT IP ADDRESS HTTP 443 443 192.168.1.4 bittorrent 6888 6888 192.168.1.8 faceblaster7 7777 7777 192.168.1.20
As in, what if I want to HOST something from my house?
It must *find your IP address*
Either
PAY FOR/HAVE A PERMANENT ADDRESS
or
DEAL WITH AN IMPERMANENT ONE
Deal with an IMPERMANENT IP ADDRESS
Reverse Proxy.
This is how you can have multiple sites/computers/urls
all at one IP address.
Talking to a computer online; typing
(in the clear)
Basically "telnet," but Encrypted (Keys, Passwords, or both)
Now, the de facto standard, and applies to a lot of ideas (but mostly 2 and a half)
Standard way to connect from one computer to another
ssh username@remotemachine.com
Anything that can go through the net;
Just like CP, but remote.
scp username@host.com:/home/user/localfile /home/username/remotefolder
Many Linux file managers have this built in
You can set it to work WITHOUT PASSWORDS;
and it's SAFER.
Whoa.
(This is all about public and private keys)
but your final likely won't work here..