Super Subnet Configuration?

Well, technically, you can't get exactly what you're asking for, because the 10.0.28-30.x subnets are non-contiguous with the 10.0.8.0/22 network.

So you have a choice to make:

1. You can set the mask to 255.255.224.0. This will allow all networks between 10.0.0.0-10.0.31.0 to get through, but it will cover your range.
2. You can use two lines: one for 10.0.8.0/22 (255.255.252.0), and another for 10.0.28.0/22. This will allow both ranges, but you will still also be allowing the 10.0.31.0 network through.
3. You can use 4 separate lines.

Those are really your choices. So ask yourself: How important is it that I allow only those specific networks to get through? Because that's going to answer your question.

is it possible to use following if I change to same subnet range?

10.0.28 - 30.x / 255.255.255.0 and 10.0.8.0 / 255.255.255.0 can be route by 10.0.0.0 / 255.255.255.0?

for example. 10.0.0.0 255.255.255.0 10.0.8.1

Thanks

Not if I understand what you're asking correctly. No.

10.0.0.0 with a 24-bit mask (255.255.255.0) means the 10.0.0.0 network (i.e. 10.0.0.1 - 10.0.0.254 effective host addresses). With a 24-bit mask on that subnet, you wouldn't be able to see 10.0.8.0 at all.

Let's back this up a couple of steps.

Based on your last question, it sounds like you don't really have other networks in between. You just want a single line that would allow you to route all the desired subnets through. But you don't really care about allowing other subnets through because they probably don't exist - is that right? In other words, you want to allow 10.0.8-11.x through, and you want to allow 10.0.28-30.x through. But you may not really be concerned about whether you allow 10.0.22.x or 10.0.31.x through, because they don't actually exist in your network. Would that be a fair assumption? Or do those other networks exist, and you're actually trying to limit which networks can be routed through the VPN?

Actually, I just reread your original question, and it might make the most sense to describe what the network looks like (or draw it and add a diagram.) Because while I'm giving you the right subnet advice, that may not mean that it will help you with the VPN.

What networks are on each side of the VPN?