route add don't support CIDR

my ip : 10.193.6.53 /24
gw: 10.193.6.254

D:\Profiles>route add 192.168.100.65 mask 255.255.255.0 10.193.6.228
The route addition failed: The specified mask parameter is invalid.
(Destination & Mask) != Destination.

D:\Profiles>route add 192.168.100.0 mask 255.255.255.0 10.193.6.228
Success

route add ???CIDR wrote:
> my ip : 10.193.6.53 /24
> gw: 10.193.6.254
>
> D:\Profiles>route add 192.168.100.65 mask 255.255.255.0 10.193.6.228
> The route addition failed: The specified mask parameter is invalid.
> (Destination & Mask) != Destination.
>
> D:\Profiles>route add 192.168.100.0 mask 255.255.255.0 10.193.6.228
> Success

192.168.100.65 is a host address. It refers to a single host machine.
Its netmask must be 255.255.255.255 .

192.168.100.0 is a subnet address. Its subnet mask of 255.255.255.0 is
correct .

The route add command supports VLSM (Variable Length Subnet Masks) but it
will recognize only proper network id associated with a subnet mask. For
instance, the correct network id for the block you are trying to route is
192.168.100.0 with a 255.255.255.0 or /24 subnet. If you wanted to do a
smaller block, say 192.168.100.64-71 you would have to specify
192.168.100.64 with a 255.255.255.248 or /29 subnet. You would not be able
to use 192.168.100.65 in either case even though they are legit IP's within
the range of the subnet.
It just means you need to know how to calc what the network and broadcast
id's are for a given subnet prior to adding that subnet block to the routing
table.
Regards,
Ed Horley
Microsoft MVP Server-Networking

"route add ???CIDR" <(E-Mail Removed)> wrote in
message news:E4A2A6EB-687C-4707-91F9-(E-Mail Removed)...
> my ip : 10.193.6.53 /24
> gw: 10.193.6.254
>
> D:\Profiles>route add 192.168.100.65 mask 255.255.255.0 10.193.6.228
> The route addition failed: The specified mask parameter is invalid.
> (Destination & Mask) != Destination.
>
> D:\Profiles>route add 192.168.100.0 mask 255.255.255.0 10.193.6.228
> Success
>