Subnetting tips and tricks

Actually, I think we already started that. I know both Sahirh put a couple of tricks out there a while ago (although not in one of the tutorial sections - that would make too easy to find - people might appreciate it more if they have to work for it. :lol: )

hi guys...i looked at the examples in the book by lammle...and tried to figure all the tips into well one picture....i think i got most of it:)

The trick is to do some subnetting to learn it. You can confirm your results with a subnet calculator.

Start by looking at your own IP and netmask and calculating which subnet you're in, as well as what your network address and broadcast address are, and what are the valid hosts.

Lets do an example:
203.199.10.68
255.255.255.192

Subnet size: 256-192 = 64.
Subnets are : 203.199.10.0 (invalid for Cisco), 203.199.10.64, 203.199.10.128 etc..

Thus our IP (.68 ) falls in the 203.199.10.64 subnet. So..
Network address: 203.199.10.64

Now the subnet after ours is 203.199.10.128, so our subnets broadcast address has to be one less than that...
Broadcast address: 203.199.10.127

Since we know we cant assign the network address and broadcast address to any hosts, our valid hosts are all the IP's between these two.. in other words between 203.199.10.64 - 203.199.10.127

Valid hosts = 203.199.10.65-126

Easy isnt it ?