Help with VLSM

[ronel]

I encounter an exercise questions and read about one of Cisco Books.

I am just confused about what they mean if they said "Larger Subnet means Shortest prefix length and Smaller Subnet means Longest Prefix Length"

Isn't the opposite ways? When you say, Larger Subnet means Long Prefix Length and Smaller Subnet means Shorter Prefix Length?

Can someone clarify this?

[Big Evil]

Lets look at what a prefix length is mate. The prefix length is just a shorthand way of expressing the subnet mask an example of this is 255.255.255.0 would be /24.

So if you have a prefix length of /16 or 255.255.0.0 this subnet (65,536 address's) is larger than the /24 (256 address's) so has a smaller prefix length. (/16 V's /24)

255.255.0.0 = /16 = more subnets (host/addresses )small prefix length
255.255.255.0 = /24 = less subnets (host/addresses ) big prefix length

So in all the small the slash notation (prefix length) the more subnets/host/addresses you will have the bigger the slash notation (prefix length) the less subnets/host/addresses.

HTH.

[ronel]

Thank you Big Evil, I just pass the exam today!!! ICND2! :p

[Big Evil]

Nice one mate, what you have planned next?

[ronel]

I think I'm going to take CCNA Security next. I kinda interested in Security too :)

[Big Evil]

You can never know too much security mate, there will always be a need for it. The CCNA SEC is good, but there is not much ASA stuff in there and they save that for the CCNP SEC.

[ronel]

Hi! Yes, I am also thinking after CCNA Security to go for CCNP first, then CCNP Security. I do have some broad background on Security. As, I have Security+


Cheers!
Ronel:)

[Big Evil]

The strong R&S will always shine, you need this as you main stay unless you are looking for more consultant in one big area. As much as i love the Cisco stuff, not large compaines i got into have Cisco as their main secuirty/firewall. The princples of the secuirty remain, but you want to look at Checkpoint/Juniper also.

[ronel]

Yes, I am also considering Checkpoint, CEH and VMWARE afterwards. I also agree that CCNP always shine whenever you go. Same as with Security, will go hand and hand with R&S.


Thanks!
Ronel

[Big Evil]

Whatever you decide mate, i am sure you will do well.