So in the Internet, how is it that networks on different networks can communicate with each other? What exactly do you configure on the router that allows it to be able to allow two two different networks communicate with each other? Is a SOHO router capable of this?
Re: Cannot access server in different subnet
11 years 1 month ago #22221
Each IP host has a routing table that defines through which gateway (router) it will access each network to which is no part of. Routers, likewise, have such a table, only that they are configured to also accept traffic from other hosts in one network and forward it to hosts in an other network. Of course they need to have an interface to every network that they will forward packets to and from, in order to do that. Any embedded router and any PC, as long as they have the appropriate interfaces to connect to of all our IP networks (commonly Ethernet adapters, but can also be other types of physical or virtual interfaces), can do that job. The table can be populated statically, by the administrator.
In cases where our network contains many routers and many sub-networks, like in the case of Internet, populating and maintaining the routing table manually is painful, that's why there are several Dynamic Routing protocols, that handle the automatic negotiation to transfer routing information from a router the an other. According to the
approach, it is wise to not use dynamic routing unless you have to.
For detailed information you can check the tutorials for routing and IP in this site