What are the rules for connecting routers?

Question

Computer networks

Suppose we have network A which is connected to router X and network B which is connected to router Y.
What ips should I assign to the routers' 'bonding' ports in order to connect these networks?

Answer 1

Globally available - those that your provider gives you. If you already have AS - then you would not have asked this here, but asked your network administrator. LAN - any addresses from gray subnets.
The main thing is that both routers know where to send packets.
Router X must know that network B is reachable through host Y.
Router Y must know that network A is reachable through host X.
The IP addresses of hosts X and Y themselves do not matter, nor does the number of these addresses. Then there is only the question of how to do it so as not to prescribe these routing tables manually and all sorts of redundancy schemes, load balancing, cost.
It if without NAT, it is simple to transfer packets among themselves.

Answer 2

Any addresses from the public network

Answer 3

The "bonding port" addresses of the routers must be on the same IP network.
In your case, 1 router is enough to connect two networks.

Answer 4

More specifics) Routers see each other directly / through the provider, etc. Are there only 2? If more, it makes sense to raise dynamic routing. Assigning addresses is not enough, you must also register routes, and on both sides.