question on subnetting....

[sambuca69]

I've been practicing some subnetting on subnettingquestions.com - Free Subnetting Questions and Answers Randomly Generated Online and I'm a bit confused on an answer they had to a question.

Question was: What valid host range is the IP address 192.168.155.4 255.255.255.248 a part of?

Their answer: 192.168.155.1 through to 192.168.155.6

Now, I came up with 192.168.155.1 - 192.168.155.7. The IP ranges should be every 8 IP addresses, so you have an initial range of 192.168.155.0 - 192.168.155.8. You can't use the first or last IP.

What am I missing here?

[hodgey87]

Yeh there answer is correct if you look out how it all forms out

0 8 16 24 etc
1 9 17 25 1st usable
6 14 22 30 last usable
7 15 23 31 broadcast

you cant use the actual subnet number ie 0, 8, 16 and you cant use the broadcast for each subnet ie 7, 15 etc.

[blackninja]

The subnets go up in mutiples of 8:

192.168.155.0
192.168.155.8
192.168.155.16
etc.

therefore:
192.168.155.0 (subnetwork address, not assignable)
192.168.155.1 (valid address, assignable)
.
.
192.168.155.6 (valid address, assignable)
192.168.155.7 (broadcast address, not assignable)

192.168.155.8 (next subnet address)

Hope thias helps

[sambuca69]

Ahhh..... broadcast address. I overlooked that. Many thanks for clearing it up

[mikej412]

Originally Posted by sambuca69

The IP ranges should be every 8 IP addresses, so you have an initial range of 192.168.155.0 - 192.168.155.8.

You have 9 addresses there. The first range is 192.168.155.0-192.168.155.7

Take out the network address and broadcast address and you have the host addresses that match the answer given by subnettingquestions.com

[Kaminsky]

Originally Posted by sambuca69

Ahhh..... broadcast address. I overlooked that. Many thanks for clearing it up

Nope ... You thought initial range was 0 .. 8

Originally Posted by sambuca69

... so you have an initial range of 192.168.155.0 - 192.168.155.8.

It isnt, 8 is the start of the next subnet.

Thing about subnetting is you get loads of shin bruises where you keep having to kick yourself

[blackninja]

Originally Posted by sambuca69

Ahhh..... broadcast address. I overlooked that. Many thanks for clearing it up

Don't worry, I really struggled with subnetting at first, then literally one night while thinking about it - it all just clicked.

When it does click, you will think that you where stressing for no reason.

Just keep at it.