How to combine the local networks of two routers into one?

Question

Computer networks

Hello. Faced a problem. There are two routers. On the first router, IP addresses like 192.168.1.x, on the second - 192.168.2.x. I'm trying to connect them to one local area network like LAN-to-LAN. But there is a problem. Routers do not see each other. And you want to make sure that devices connected to one router can see devices connected to another. I say right away, do not suggest that I use one of the routers as an access point / disable DHCP on one of the routers / connect them via LAN-to-WAN. I want to do exactly the union of two networks into one.

Answer 1

Depends on router models. In general, each router must know through which address to send to the neighboring network (gateway address).
Here the question raises more - each router needs one port - look towards the neighboring network, and there is usually only one WAN port (for budget versions). How will the Internet get into such a network? if both WAN ports are busy looking at each other?
The secret keyword is ROUTING.
On two Deshman routers, this can be done in the right way - there is almost no way (you can take the third one, then it will work, but with difficulties).
The starting point, when it is at least somehow realistic to implement - on mikrotiks (from 1500 rubles)
New zuxel firmware also allows you to work quite flexibly (but not at hand)
On normal routers, at least the SOHO segment, everything will most likely be fine.
Cisco and others like them - will be very good. I attached the scheme on
ciscos

Answer 2

You can solve the problem with route 1, 192.168.0.0/21

Answer 3

There is only one solution "on the forehead", independent of router models:
1 The first network remains as it is, and its router (No. 1) connects to the Internet.
2 The second network is plugged into the "first" one:
2.1 On router No. 1, we specify the length of the DHCP range (so that it does not end up at 10 addresses), if anything, we increase it in accordance with the total number of wired and wireless clients of BOTH networks.
2.2 It is desirable, but not necessary, for router No. 2 (second network) to change the IP to 192.168.1.2 (should be free) - just so that later it can be administered.
2.3 Be sure to disable DHCP on router No. 2.
2.4 We pull the cable from router No. 1 to router No. 2. We stick it in BOTH routers into the LAN (not WAN) ports (in both). On the second router, the WAN port remains free.
2.5 If desired, we terminate the contract for connecting point No. 2.
3 PROFIT. We get a continuous address space 192.168.1.* in the entire network. The traffic goes locally.
Difficult option:
1 We buy routers with IPSec support (for example, Zyxel of the Keenetik series), do not change anything, do not reconnect, leave the Internet at both points.
2 Set up the "mouse" on both IPSec each other.
3 PROFIT. Networks are different, traffic goes through the Internet.

Answer 4

There is an option.
1. A third subnet is invented, into which routers are connected by WAN ports (each, of course, needs to be assigned its own IP).
2. NAT is disabled on both routers;
3. Each router adds a static route for a foreign subnet; as the gateway, the IP address of the corresponding router in the third subnet is indicated;
4. Packets are checked using tracert/traceroute.

Answer 5

Two routers are connected via LAN ports. The network mask on all devices on the network is 255.255.252.0
That is, router1 192.168.1.1 255.255.252.0
That is, router2 192.168.2.1 255.255.252.0
Well, any device on the network has such an ip 192.168.1.10/255.255.252.0 and that's it.

Answer 6

I would suggest using vlans, if routers can do them, then it is quite possible to combine them through any ports. You see, it would be useful to understand what equipment is used - a lot depends on this.

Answer 7

It is not clear what kind of routers are used and what functionality they have.
On Linux, I raised a bridge (bridging 802.1d) between two remote gateways (essentially routers), which is essentially equivalent to connecting LAN ports on physical switches.

Answer 8

there is another option

Answer 9

recently I also searched for this information and only after viewing the instructions https://www.youtube.com/watch?v=qo8zBPybcsk was able to quickly set everything up