Another question.
I set my VM router to modem mode and then this leads to an unmanaged switch in the lounge.
The switch leads via a wire to an Asus router in the office with a hardwired PC and wifi which is great.
When I plug my kodi or laptop into the switch in the lounge I can't connect to the internet from the switch?
Do I need to use a second router in the lounge.
Jeeze this is confusing.
Doesn't the modem output internet?
Explain like I am 10, possibly 5. Thanks pod
You can't do that. Full stop. TLDR at the end
...
A group of connected devices is called a network.
Your home is one such network, hence Local Area Network, or LAN. Your home network (or LAN) is made up of all your computers, laptops, tablets, phones, printers, TVs or anything else with a network connection. Nowadays, these local devices will all be connected together via their network ports to a central
switch which allows them to speak to each other across your network. The switch can be a stand-alone device, or it can be built into your router.
This type of network is a
private network. You own and control it, and all the devices on it. Only you can see what happens there; for example who is connected, or what traffic is being sent. All the traffic (communication) between the devices on a local private network stays within that network. It doesn't go outside of the network (eg to the Internet or someone else's house).
Private networks assign devices on them an IP address from one of a few specific universally-agreed ranges of numbers, called reserved private IP address spaces. These ranges are 192.168.0.0/16, 10.0.0.0/8 and 172.16.0.0/12. So, your local network devices may have addresses like 192.168.1.2 or 10.0.0.5 etc. Private networks can only see (send or receive) traffic on their own subnet - so devices on a local network addressed as 192.168.1.X can not see or talk to devices addressed with 10.0.0.Y, and vice versa. Your local network will have a single range, and stick to it.
Private addresses like these will never be seen on the normal public Internet (Iran excepted), and are reused inside private networks the world over. A switch connects
local devices together. It keeps track of all the local devices on the local private network, by maintaining a list of their private IP addresses and corresponding MACs (hardware IDs uniquely assigned to every network port at manufacture). This allows those devices to talk to each other across the local network.
Originally all networks were private local networks like this, but in time - years ago, now - some networks were physically joined together across physical space, bridging the gap between them. This made information sharing easy. But what about all the conflicting devices and local IP addresses? Well we didn't create one global private network. That would have been hugely messy, and insecure. I don't want someone on the other side of the world to have access to my printer, my NAS full of family photos or anything else and besides, if I send a packet to 192.168.1.1 (eg my router) will it go to *my* 192.168.1.1 or yours?
No, we need a second network - a shared, public one -
alongside the individual private networks. That's where public IP addresses come into play. If you recall, all devices already had a local private IP. Anyone wanting to join this interconnected public network also needed to also have a unique public IP address to identify them to other devices in other networks, maybe on the other side of the planet.
Now, by having a private IP and a public IP, you could send traffic either locally and privately (between your own devices using their private IP addresses), or across the wider shared public network (between one public IP in England to another public IP in, say, Iceland).
Across the world, all the devices with public IP addresses (routers, web servers etc) are part of the shared
public network - the "
INTER-connected
NETwork" of devices, aka the Internet. So Virgin Media have another network, made up of all of their devices. Google, Cloudflare, M247, Microsoft, Amazon and all the other people, companies and organisations around the world also have their own networks.
Remember how a switch connects your local
devices and allows them to communicate? Well as a switch connects together
devices on a local network, a
router connects together different public
networks, using their respective public IPs.
These public IP addresses (numbers) are assigned by an external authority, and never reused. Each is unique, and every device on the public Internet needs one. At first, every single networked device on the planet got its own public IP address, but when the Internet and web exploded in popularity we started to run out of IP (v4) addresses very quickly. After all, IP (version 4) addresses are only made up for four digits (0.0.0.0) with each digit being a number between 1 and 255. Some combinations (ranges) are already reserved for specific uses, like with the private IP ranges already discussed, but there are others too. This leaves only a limited number of addresses left available for general public network use worldwide.
To get around this, routers started to act as a proxy to share one public address with all the devices on the local private network hiding behind it. This meant that instead of your house needing (for example) 20 IPv4 public addresses, one for each device, you could assign just one - to your router. Your router would then be the only device on your network with two addresses - one private address, as with all your other local devices (eg 192.168.1.1), but also a public IPv4 address, to enable it to see and be seen on the Internet.
By keeping a record of all traffic going in and out of it, a router can now act as a middle man sending and receiving traffic between the private network and the wider public network, fetching information/data/packets from the Internet on behalf of the private clients on the local private network that it serves. This is called Network Address Translation, or NAT.
With that in mind, suppose your PC (which only has private IP address 192.168.1.10 and no public IP address) wants to ask for data from google.com. Google is on the public Internet, to which it has no direct access due to not having its own public IP. So rather than connect directly, the PC will ask the router, its
gateway to the Internet, to send out the request on its behalf. Think of the router as that one guy in the village who has a telephone, so everyone goes round their house to ask to make calls.
The router will record that local device 192.168.1.10 is requesting info from google.com at, for example, public address 8.8.8.8. It will make the request on the local device's behalf, and then when it gets a reply from Google it'll check its record/table, and say 'Yes, 8.8.8.8 replied - this was for the device at 192.168.1.10'. It will then send the data (reply) from Google to the correct device.
Meanwhile, the router is doing this multiple times per second for every device on your local private network. This way, one single public IP address gets shared by many private devices hiding behind it. That means we can make public IP address last longer/stretch further, and everyone still gets to go online. That's where the NAT (Network Address Translation mentioned earlier) comes in. Your router is translating requests between your local network addresses and the public Internet IP address.
Your modem (Super Hub in modem mode, in this case) is just a bridge to Virgin Media's public network, basically the metaphorical hand that VM extends to give one of your local devices a single public IP address. Since VM only offer each account one IP address, you probably want to make that device your router which, as above, can share the connection between your whole network.
You
could just plug in one random device like a PC, but then that device gets your one and only public IP address and then (1) is directly connected to the Internet with a public IP and likely woefully lacking in security to defend itself from attackers, and (2) means you can't have any of your other devices online.
So, we're back to wanting a router to handle things for us and share the connection around your whole network. You have a router, so you're good to go... aren't you?
...
Think back to how you've set up your network. What you've done, and what you're describing, is extending the modem (via a switch) to a different room. We now know that switches connect all the devices plugged into them, but we also know this means that they are also like an extension cable to branch out a single port to many connected devices.
When you plugged in a switch to the modem's port, you made that one port expand to fit however many devices the switch can take. So now we have, say, 7 devices all trying to connect to the single modem port to claim a single IP address so that they have an identity and can 'talk' on the public network.
In your case, the router takes the single available public IP address from VM via the modem. So far, so good... but can you guess now why your other devices on that switch aren't working? They don't have a public IP address and aren't
behind (connected to) a router with NAT, and so can't share the router's connection to either the Internet or the local network! They're stranded.
A switch should
always be behind a router, never in front of it - or else it's useless. The devices connected to a switch need IP addresses, and that will only happen (ordinarily, in a home network) when they connect to an upstream router.
TL,DR: Rip everything out and plan your network again. Connect the Super Hub (in modem mode) directly to the router via an Ethernet cable. Now connect your switch to the router, and all your local devices to the switch.
Modem > Router > Switch > Local devices.
Now, the router will snatch up the single public IP address from VM via the modem and act as a gateway to the public Internet for everyone else behind it. The switch will allow all your local devices to connect to the each other and the router. When the local devices want to talk to each other (eg sending files) they will do so through the switch. When they want to get to a website or whatever, they will do so through the switch to the router, which will use NAT to proxy the web request for them.
Job jobbed.
If this was too much for you, check out a 'How does the Internet work?' video on YouTube - it can be easier to understand when presented visually.
Dohh!
