alexis wrote: ↑Thu Jan 09, 2025 6:39 pm
Thanks again, James, very helpful as always
I'll try and reduce it down to elementals. I had mentioned earlier, the analogy of the telephone network.
The two types of network: a Domain and a Workgroup
Domain - a server is used to administrate the network, This is not usually used in a smaller, say home network with a few computers, setting up a domain isn't justified as in a domain you have a server to administer the network, and that server runs 24/7
Workgroup - all devices on the network share resources and data, but no one computer functions as a server.
The job of a server - it acts as a gateway, from the Intranet (a network in an organisation) to the outside world - the internet.
Each device on a network needs a unique ip (internet protocol) address. The server using Dynamic Host Control Protocl (DHCP) dishes out those addresses and in doing so avoids conflicts (2 or more devices having the same address)
The dynamic part of this is....imagine a company with say 100 computers and some printers etc Bear in mind, a network operating system includes a number of 'seats' as part of the licence, more seats, the more costly the software
Now imagine that company has 50 employees, so it only needs 50 seats, although it has 100 computers. But not all of those computers could be used at the same time, there are only 50 'seats' and when computer number 51 were turned on (imagine there are contractors employed on an ad hoc basis) the DHCP in the Network Operating System would say "Sorry licence limit reached - buy more seats" but, the Wages Department has closed down for the day, so the contractor could go and log in to one of those computers, but no, the wages department is a secure area and closed off, and it has 10 computers in there, not being used.
DHCP will say Hmmmm, there are 10 ip addresses assigned to computers not being used, I'll borrow ip addresses from there, or more precisely the licences, in other words I can release those licences (and ip addresses) and assign them to the other computers the contractors have just turned on.
That is the Dynamic part of things. In practice the ip addresses can remain static, but the DHCP can assign addresses as and when, you might have a 100 or whatever number of computers/devices, but only 50 in use at any one time.
Also the server is a central repository for data files, that way there is managed file sharing and backup. Depending on company policy, the server can monitor traffic going in and out of the company computers, so for example the users cannot download and install all manner of trish-trash, and viruses! if a client computer does become affected, it is far easier to isolate.
The server will also serve as a mail exchange, so all emails coming in and out of the company are managed.
Bear in mind there are many different aspects to the internet - ftp, www, telnet......etc we often think of the internet and the web as one and the same thing when in fact the internet is a suite of things, the server OS can handle any of those.
Much of the software used on client computers will just be 'front end' the data itself be kept on the server, a database being a case in point, that way each employee can have access to the database instead of each employee having a separate version on their workstation. IM have known some companies where employees would copy data onto USBs and pass them around the other users in the company to keep the data consistent. Between 2 or 4 computers, yes ok - but 50, or 1000!!!!
The Workgroup - a much simpler setup, each computer is independent of each other, they have no common central meeting point. But are connected so they can share files, and one could be assigned as a Quasi server, where shared files can be kept.
But what about ip addresses? Well each computer can be assigned a static address. But more likely, there will be a router, to connect to the internet, and that will dish out ip addresses, by way of DHCP and by way of using a NAS, a central repository for files can be kept, with the NAS having it's own address, is kept switched on and thus files be available to any user with the requisite permissions. By using a router and NAS you have sort of a toy domain, but no way as complex as a domain server
IP Addresses - typically 192.168.1.1 (up to 255) 255.255.255.255
255x255x255x255 - a lot of numbers eh - I think it stacks up to about 6 billion, that's plenty? Well not so - because the number of devices in the world is increasing, with not just computers being on the internet, but cell phones, cars etc etc etc so now we have a different system, but for our purposes lets stick with the 255.255.255.255
Some ip addresses are as good as fixed - 10.0.0.1 is often used for localhost (the server)
There are others but lets stick with 192.168.x.x (192.168.1.1 for example)
What concerns us is the last two 1.1
The last number '1' is the device number, so say you have 4 devices PC, tablet, phone, printer...so they will gt the addresses
192.168.1.1
192.168.1.2
192.168.1.3
192.168.1.4
.
.
.
192.168.1.255
and 255 devices is more than enough? Nope, what if you have a company with 300 computers (for example)
What you do is set up a subnet and you get is....
192.168.2.1
192.168.2.2
192.168.2.3
192.168.2.4
.
.
.
192.168.255.255
But you might say "Hang on a minute, my computer has the ip address 192.168.1.10" (for example)
And my pal up the road has a computer and that has the same ip address?
Yes, but that is only within your little home network, your router address though will be assigned by your broadband company, so you have a network that is a subnet of the top level network.
Instead of pinging an address, try this, the trace route (tracert) option
tracert
www.bbc.co.uk
You'll see the hops the request goes through, showing the different networks
When you add a device to your home network, you might use ethernet cable, which plugs into the network interface card (NIC) in your computer and it is the NIC that picks up the ip address from the router, but usually home routers only have 4 ethernet ports, though you can add another internet switch/hub which will have 4 or more additional ethernet ports, or more likely use WiFi where you are not limited by the number of physical ports.
Your router serves as a gateway, same as a server does. I have come across some routers that have a firewall built in, in the same way server does and the router might have basic config options, eg block sites etc
Cellphones - how do they stay on the network? Well every time you turn your phone on, it looks for the nearest mobile mast, and when you're travelling about, your phone is constantly being pinged, and as you travel you'll pass from one cell to the next, DHCP on the move, the cells being organised using a structure known as tesselation, which means there are more shared borders between cells than if the cell were circular shaped or box shaped, tesselation is octagon shaped, giving seamless contact - well most the time. Additionally, cell phones can employ bandswitching, there will be a range of frequencies available and within that spectrum are different slices of frequencies. When one frequency gets busy, signals are switched to less busy ones - as ethernet DHCP can dynamically assign addresses.
Are you still awake? Well I had hoped to keep this simple, but half way along I thought I started so I'll finished. I amazed by the technology, it's a wonder it works at all.
As it turns out putting each computer into airplane mode is what pushed me over the finish line in terms of being able to access the "other" computer under the respective "Network" tabs, which is what I tried to set up for an eternity in preparation for trying Audiogridder itself for the nth time. This site, 
