Will cross-routing work?

Question

Network routing

There is a route table in which it is written:
60.48.105.0 255.255.255.0 20
then a partially duplicated entry with (possibly) the same metric
60.48.105.123 255.255.255.255 20 is added there (automatically)
Will this route refinement be an error? Is metric important? On all systems (Windows Android Linux) is this not quite logical (butter oil) action "rolling"?
PS sorry forgot to specify the route goes to one interface

Answer 1

if you have one interface, you can pile almost anything into the routing table.. as long as there are no multiple interfaces, it's unlikely to be a problem. when they are - there will be a problem
ps although the problem can be created:
- set as DNS, strictly 8.8.4.4 and 8.8.8.8 (is it obvious that this is a subset of the "any" range? and it is. in the sense these are intersecting sets)
- let by default, everything goes to some real gateway (usually the automatically generated tables are arranged like this)
- add an entry for the 8.8.0.0/16 network with a redirect to 127.0.0.1, but with a metric lower than the default one ... exploit 5-10-15 minutes ..
- .. and now make for this record, the metric is higher than the default

Answer 2

According to the laws of the genre, the system first looks at the length of the mask, and only if the masks are the same, then the metric is used.
And if there is only one interface, then there is nothing to talk about.
It will work, but why such difficulties?

Answer 3

Sorry in the morning I thought I sent the answer, it turned out I didn’t register.
This is vpn (openvpn) to bypass blocking, the interface on the client computer is naturally 2 (Internet + vpn tunel).
On the server, it was initially configured to transfer the routing table to the client to bypass only blocked resources (the rest go directly), and so it happens that initially a whole subnet is registered in the bypass routing, for example, 65.65.65.0 with a mask of 255.255.255.0. Then I would like to add some more sites in automatic mode. And I wanted to clarify if a site with ip 65.65.65.11 with a mask of 255.255.255.255 hits - whether this will cut down the previous rule. In theory, no .. but you can’t immediately check it on Windows Linux Android MacOS Iphone. Besides it would be desirable to know in principle a working variant.