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English Forums => General Discussion => Topic started by: ajoeiam on April 29, 2023, 07:39:14 PM

Title: network understanding - - - re: routing - {solved]
Post by: ajoeiam on April 29, 2023, 07:39:14 PM
Greetings

Have looked for a good place to ask networking questions - - - - really a dearth of information out there.

Starting with a (I hope) simple question.

A router on a 192.168.1.x network serves up to 255 devices (Likely practically somewhat less but thereabouts).

A router on a 172.10.x.x network serves up to how many devices?
Title: Re: network understanding - - - re: routing
Post by: bartjsmit on April 29, 2023, 07:48:28 PM
https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing
Title: Re: network understanding - - - re: routing
Post by: ajoeiam on April 29, 2023, 09:43:42 PM
Apologies - - - - - the answer to my question may be somewhere in the suggested document - - - - - but I could NOT find it.

I still have absolutely no idea how many IP addresses can be managed from one router on a 172.10.x.x address.
Title: Re: network understanding - - - re: routing
Post by: meyergru on April 29, 2023, 10:12:21 PM
That is maybe because your question is REALLY basic. If you were going to build up knowledge by just asking questions like that, it would take you forever because you would not understand the answers.

Just to prove a point here, the answer is: 65535 (or "thereabouts").

Does that help you in any significant way? Or is the next question: why? If it is, I suggest to read a book about networking or find some educational video series about it.

Title: Re: network understanding - - - re: routing
Post by: bartjsmit on April 30, 2023, 09:31:36 AM
It's a binary calculation - the mask divides the IP space into network bits and host bits. 172.10.x.x has two octets in the network bits (172 and 10, or AC and 0A in hexadecimal) that take up 16 out of the 32 bits of the IP address. The notation for that is 172.10.0.0/16

That leaves 16 host bits. One is reserved for the network address itself - where all the host bits are zero, and one for the broadcast address - where all the bits are one. 172.10.0.0 and 172.10.255.255 in this case.

With 16 host bits you have 2^16 - 2 permutations for host IP addresses = 65534

TL:DR https://www.subnet-calculator.com/subnet.php

Bart...
Title: Re: network understanding - - - re: routing - {solved]
Post by: ajoeiam on May 01, 2023, 04:05:17 AM
Thank you for the information.

I had found mountains of information on how one didn't need to use more than the single sub-net on 192.168.1.x by using sub netting.
Couldn't find any information on how to write those addresses into a quad without needing more than a quad.

Thanking the responders.

I want a good foundation for my project(s).

Ciao
Title: Re: network understanding - - - re: routing - {solved]
Post by: bartjsmit on May 01, 2023, 08:46:00 AM
Quote from: ajoeiam on May 01, 2023, 04:05:17 AM
single sub-net on 192.168.1.x

Be careful with using common network addresses for your internal networks, such as this one. If you ever set up a remote access VPN, you will have trouble connecting to it from hotspots and friends' networks, since they often use overlapping ranges. Pick something obscure like 10.37.143.0/24

Bart...