Assume you have two servers in a private network.
Server 1:
ip: 10.0.0.10
, lives in the /24 subnet 10.0.0.x
.
Server 2:
ip: 10.0.1.20
, lives in the /24 subnet 10.0.1.x
.
Assume these two servers cannot reach each other, there is no route. I would normally say "10.0.0.10 is not routable from 10.0.1.20" but I realize now that this might not be the proper terminology.
It seems like the term "routable" is actually used to refer to the difference between public and private ips, ie, "8.8.8.8 is routable, 10.2.10.129 is not".
So what exactly is the correct term for my original example? "Reachable"? "Reachable" doesn't really sound right for some reason.
You could say 10.0.0.10 has no route to 10.0.1.20. Since your example is that there is no route between 10.0.0.0/24 and 10.0.1.0/24, you could say that (as opposed to more specifically saying 10.0.0.10 has no route to 10.0.1.20 and 10.0.1.20 has no route to 10.0.1.20.
There are two possibilities, that are implicitly being discussed:
While there could be a single host route from 10.0.0.10 to 10.0.1.20, that isn't the case.
While one network could have a route to the other and not the other way around, that isn't the case.
If the two networks are on the same switch but on different VLANs, you could also say they are logically separated.
If the two networks are on different switches, you could also say they are physically separated, provided that the two switches are not connected.