Can I create a network without a router?

Question

I'm doing a quite simple network setup (hopefully): a file server and a Wi-Fi/AP.

The AP which I've got is a biz-grade AP, much more robust, but it is without a built-in router (so no standard DHCP server builtin)...

It does have a 'hotspot' mode, which (when activated) hands out DHCP over Wi-Fi, and routes them to the gateway port (essentially a walled-off guest Wi-Fi network running on the same AP, not allowing access to the LAN).

My hypothesis is this... I think I can make my network like this:

Set server - static IP 10.0.1.254, on a 10.0.1.0/24 network. Its gateway would be 10.0.1.100 (the AP)

Set AP - static IP - - 10.0.1.100, on 10.0.1.0/24 network. It's gateway IP would be 10.0.1.254 (e.g. the server).

Set AP "hotspot" to serve out DHCP for WIFI clients, effectively sending that traffic to its gateway (10.0.1.254).

The AP would enable the hotspot network, thereby handing out DHCP to Wi-Fi clients, and passing all service directly to the 'gateway' (the server), and the server would in turn pass all service directly to the AP.

*I also don't need this network to connect to the web - it's a closed network designed to accomplish a single specific task...

Is this possible? Will the server actually talk to the AP in this manner? Do I HAVE TO have a router just to make this work?

Answer 1

Yes, surely you can create a network without using routers.
Routers are used to filter and forward packets from one network to another network. The network you will create will only be able to communicate with the nodes that are inter-connected with each other via the Layer-2 Switch.
Default gateway is used whenever a packet is not destined for the current sub-net you are in (which means the destination IP of the packet exists on a different sub-network). If the packet belongs to the same sub-network you are in, then routers won't be required to deliver the packet. You can consider this. Suppose you want to send a package (like a greeting card, a gift, or something else) to someone. If the person lives in the same building (or even the same city), then you can directly deliver the package to that person. If the person is living very far away and don't know exactly how you can each the person, then you will be taking help of some company that provides courier service (like FedEx).
You can find the IP addresses, that belongs to your sub-net by using ipconfig or ifconfig (for Windows or Linux respectively). It shows you IP address and the sub-net mask, which can be used to find the range.
The image below shows a typical network that can be created just by using Layer 2 devices (no routers). It is made using Cisco Packet Tracer software.

Answer 2

Routers route traffic between networks. If you only have one network, you don't need a router. A gateway is usually a router because it is used for traffic where the layer-3 destination is on a different network. If you only have one network, it doesn't matter to what address the gateway is set.

Answer 3

can i create a network without a router?

Yes. The basic component of a network is a link-layer device that several endpoints connect to, for example an Ethernet switch or a WiFi access point. Once the endpoints are connected, they can communicate with one another over the network.