How to use two network range in single network?

Question

I have a single private network 10.51.8.0/23 (say NetworkA). On the physical network running NetworkA I have single host (say HostA) with IP 172.16.0.24.

My intention is to reach HostA from NetworkA.

test@test:~$ route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         10.51.8.1       0.0.0.0         UG    100    0        0 eno1
10.51.8.0       0.0.0.0         255.255.254.0   U     100    0        0 eno1

Is it possible to create a new interface mylocal with Destination 172.16.0.0, Gateway 0.0.0.0, Genmask 255.251.0.0, Iface eno1?

Is the above approach valid and satisfy my use-case? If no kindly propose your opinion on this.

Answer 1

A road junction between two roads, needs to be on both roads.

They can be on the same physical network (or not). In ether case, you need a bridge/gateway/router between the two logical networks. This gateway has to be on both networks, physically and logically(so have an address on both), and configured as a router. And every device on the two networks needs to be informed of this route.

Answer 2

Yes, it is possible. At least Linux allows you to run two separate networks on the same physical network. On IPv6 this is in fact standard procedure, with a global address and a link local address assigned to each node on the network. But it works using IPv4, too.