VLSM

[L8NightHype]

Hello...

I am hoping some one can reply with a link or resource to VLSM.

I am close to understanding, but I need to be sure. A networking calculator won't help me here. I need to understand the concepts.

Take for instance this address: 192.168.16.0/22

Now the mask would be 255.255.252.0 for a /22 network. Correct? But what about the subnets within this address? If I am right, this /22 allows for 62 subnets and 1022 hosts per net.

Now then, does this mean since the right most network bit is over the the 4 position, in the third octet...the subnets are ranged in order of 4's?

For instance...the first network (In reference to the above address) would be 192.168.0.0 But this one can't be used since it is the 'zero' net, is that right?

First Useable Subnet: 192.168.4.0
Host Range: 192.168.4.1 - 192.168.7.254

Second Useable Subnet: 192.168.8.0
Host Range: 192.168.8.1 - 192.168.11.254

...and so on up to 62 usable subnets with 1022 hosts per subnet? The last net being the broadcast.

Any advice would be appreciated. Please correct me where I am wrong. Or drop a link on me.

Thanks in advance...

:D

[Midknyte]

I think that's right.

you are using 6 bits for the network, so the mask is correct.
128+64+32+16+8+4=252

2^6-2=62 subnets
2^10-2=1022 hosts

256-252=4 increment of subnets (4,8,12,16.....)

first network id: 192.168.4.0
valid hosts: 192.168.4.1 to 192.168.7.254
broadcast for first network: 192.168.7.255