subnet mask question

if i had to choose an answer i will choose 1 and 6 using ur explanation of id and broadcast please correct me if i am wrong?

thanks man

The correct answers are 2, 3 and 4.

1. is the broadcast address for the subnet x.y.z.0 and
6. is the subnet I.D of the subnet x.y.z.192

2. is correct because it lies in between x.y.z.64 and x.y.z.96 and it is neither the first or last address.

3. is correct because it lies between x.y.z.32 and x.y.z.64 and it is neither the first nor the last address in that subnet.

4. is also correct because it lies btwn x.y.z.64 and x.y.z.96 & its also not the first or the last address in that subnet.

NB: The FIRST and LAST address in ANY subnet or network CANNOT be used.
Just like u cannot assign any host the address 192.168.1.0 or 192.168.1.255 because they are the first and last address in the network 192.168.1.0 (255.255.255.0) - Default class C mask

Clearer Now? The rain is gone i can see clearly now. Thanks losh i have a better understanding @ this point? Will digg deep on firewall.cx column on Subnetting...


Thanks

wait wait wait
@ losh

I was going over the whole post again from the initial to the last. I dont get ur defence on why it's not 1 and 6. I agree it's not 1 and 6 but i want to knw why am not clear with ur why?

Losh Wrote:

1. is the broadcast address for the subnet x.y.z.0 and
6. is the subnet I.D of the subnet x.y.z.192

You said 1 is the bcast add for subnet x.y.z.0 and 6 is the sub id of subnet x.y.z.192. My question is why did u use .0 in ur defence why 1 is not the answer. in the initial .0 was not use in 1. .192 was used in 6. So where did the 0 cometh from?

Sorry Losh but man i eat until i get filled not until i am half - filled. Nah.

Please Fill me up?

You said 1 is the bcast add for subnet x.y.z.0 and 6 is the sub id of subnet x.y.z.192. My question is why did u use .0 in ur defence why 1 is not the answer. in the initial .0 was not use in 1. .192 was used in 6. So where did the 0 cometh from?

Ok, more than glad to help here. I'll explain this extensively.

Lets take each choice and scrutinize why or why not its a correct answer.
For choice ( 1. ) 15.234.118.63 with a subnet mask of 255.255.255.224 :
We have agreed there are 32 hosts in every subnet given the above mask. With this specific address 15.234.118.63, the first subnet will have to be :
15.234.118.0.............the second will be :
15.234.118.32...........the third will be :
15.234.118.64...........the fourth will be :
15.234.118.96...........etc.
you will notice here there are 32 hosts in every subnet.
In the first subnet : 15.118.234.0 , the subnet I.D is 15.234.118.0.
The first usable address in this subnet is 15.234.118.1 and
The last usable address in this subnet is 15.234.118.62 hence
The broadcast address in this subnet is 15.234.118.63, therefore
Option ( 1. ) is ruled out as the correct answer because a broadcast address cannot be assigned to a host. Thats why i said its the broadcast for x.y.z.0 meaning 15.234.118.0.

For choice ( 6.) 217.63.12.192 with a subnet mask of 255.255.255.224 , the first subnet will have to be :
217.63.12.0..............and the second will be :
217.63.12.32......................the third :
217.63.12.64....................the fourth :
217.63.12.96...................the fifth :
217.63.12.128...............the sixth :
217.63.12.160.............the seventh :
217.63.12.192...........the last :
217.63.12.224

You will also notice that there are 32 hosts in each subnet above.
Choice (6.) 217.63.12.192 falls in the seventh subnet (217.63.12.192) and in fact is the subnet I.D of that subnet.
The first usable ip address in that specific subnet becomes 212.63.12.193 and
The last usable ip address in that specific subnet becomes 212.63.12.222 and
The broadcas ip address becomes 212.63.12.223.
Therefore, option (6.) is also ruled out because its not a usable host ip address, its the subnet I.D for that subnet.[/img]

hmmmmm :idea: thanks losh i am reading tru...

Thank u for ur good time.

... Why are u stingy with answer (lol) those are CCNA questions i guess so may be the dude is reading up and needs quick help?

I was "stingy" because the original question implied to me:

"Help, I have a homework question from my tutor that I can't answer. Can someone answer it for me and tell me how you worked it out?"

I don't mind helping someone out (goodness knows how much help I've received here as well as elsewhere!) but I'm not going to just answer questions when they are within my capability. I saw a comment a while ago:

"Tell me and I will forget. Show me and I may remember. Involve me and I will understand."

and I firmly believe that this is the best way to learn.