[Melissa]

I basically do a networking class additional my choice

But my tutor has set us some questions to practise on now most of them are okay ish but he set us one real bugger he actually gave us the answr but said see if any of us had any idea to explain why

I will when i get chance show my sister obviously but its not likeley to be today and maybe not tomorrow.. I know shes very pre occupied today since its her anniversairy for when she met her partner. Plus it sounds like a mental one so I dont wanna like wind her up on her night off. I shown my normal tutor at college and he couldnt work it out


heres teh quetion

Your company has leased the network 138.16.0.0/21. You want to subdivide this network into 10 evenly sized subnets. No single subnet will ever contain more than 100 users. You do not use NAT or private network addresses. The default gateway is always the lowest possible user address on the subnet. You use DHCP for your client PCs, but your servers are configured manually. The 10 lowest IP addresses on each subnet are excluded from the DHCP scope so they can be used for manual configuration. Which of the following configurations is a valid server?

A. IP Address: 138.16.1.5
Subnet Mask: 255.255.255.0
Gateway: 138.16.1.1

B. IP Address: 138.16.8.5
Subnet Mask: 255.255.255.128
Gateway: 138.16.8.1

C. IP Address: 138.16.3.133
Subnet Mask: 255.255.255.128
Gateway: 138.16.3.129

D. IP Address: 138.16.1.134
Subnet Mask: 255.255.255.128
Gateway: 138.16.1.128


The correct answer is C..

any ideas? this subnetting just confuses teh crap out of me..

by the looks of things on liek scythes thread a few of you know some stuff so u might be able to help.

[Chantelle]

Shizz thats ... very tough!! I cannot even believe he gave you that question with the level your at..

Normally when I had these kinda questiosn on exams you can normally whittle them away and easily see th right answer.. but so far all I can say is that A I can see definataley isnt right... its a single subnet ..

Ill get me subnet calculator out and have a look see what I come up with as I think its liekely a maths thing on he other 2

[Chantelle]

okay B is wrong.. as its the wrong network address shoudl be 138.16.1.* like the others..

D is wrong as the lowest IP address is 138.16.1.129 and the gatewat is set to 128..

tough question but well its just a very tricky question to be fair.

[Grimm]

pshh its easy

eeny
meeny
miney
MO!!

its C!!!

WoOoOoOoOoT!!!

[Melissa]

okay I still do not fully sure that subnetting seems like a well hard thing to learn I got the thing u PMed me before about classes does it relate to that?

[Gatotsu]

Having a look at the title of this topic I thought I could help.. but eh..bleh. I am not at that level yet in my network studies, a really kinky question

[Squall]

well mel the first sets of numbers like have to be static u get me

so if its 192.168.1.2 (ino it said dont use a nat) then u ahve to take of the 2 and give it anothe number say 3 meaning any information will go to 3 and not 2. so ti allways ends up like this

192.168.1.2

192.168.1.3

192.168.1.4

just have to take of the end to see the subnet

192.168.1.*

(* being the number you will have to change in order for it to work on the network )

[Melissa]

it would be a static address anyway since it was a server and it said set them up for manbual configuration..
its a tough on i just think chan said it cant be D cos the ip address is out of range on teh gateway although the ip address was setup fine

but im still a bit confused

[Squall]

yea well she in the networking queen so id go with what she advises, though mine was just an example dont sue that as a answer lol

[Chantelle]

well mel the first sets of numbers like have to be static u get me

so if its 192.168.1.2 (ino it said dont use a nat) then u ahve to take of the 2 and give it anothe number say 3 meaning any information will go to 3 and not 2. so ti allways ends up like this

192.168.1.2

192.168.1.3

192.168.1.4

just have to take of the end to see the subnet

192.168.1.*

(* being the number you will have to change in order for it to work on the network )

I think your getting a little confused although you are actually right. I think what your saying is of a Class C Subnet which is as example 192.168.1.0 /24 (or 255.255.255.0) like you said the first 3 octels are not to change

but this question is Class B so example of taht is 138.16.0.0/16 (or 255.255.0.0) however to split up the network into more than one subnet.. jeez this is hard to explain.. they have super netted it.. i find it hard to get my head aroudn sometimes let alone explain

By using 255.255.255.128 you are using a Class B sunet and splitting it up into subnets since they only have 10 subnets its will be

138.16.0.0 - 138.16.0.127
138.16.0.128 - 138.16.0.255
138.16.1.0 - 138.16.1.127
138.16.1.128 - 138.16.1.255
138.16.2.0 - 138.16.2.127
138.16.2.128 - 138.16.2.255
138.16.3.0 - 138.16.3.127
138.16.3.128 - 138.16.3.255
138.16.4.0 - 138.16.4.127
138.16.4.128 - 138.16.4.255

I have discussed this with anoteh person and we both got our head around it.

A we know is wrong its class C its just wrong
B is outside the network scope thats like if it was on the 16th address range but they only have 10
C is okay the Ip address is on the 8th network , the mask is right the gateway is okay its the first IP address in its subnet
D The p address is okay its in the 4th network, the mask is fine but the gateway is in the 3rd subnet.
B

[Melissa]

I thought you was suppose to be on holiday this week.


okay I think it sorta makes sense but given a simialr question id probabaly still completeely fold.

[Squall]

sometimes it goes over my head chan but i understand what you mean. i was just showing an example of the subnet defenition more clearly or in a less detailed easy to understand way :S but yea you are right ( yea cause i bet i new this from the start my ass ) lol

[Melissa]

tbh chan said to me its better for me (and maybe yoursrlf I dunno perhaps the likes of you if your starting ur mcsa) but anyway for me to master the main general stuff first as this is kinda advanced and even subnetting can give her a head ache and a half she had to converse with another before they both agreed..

ill pass this onto my tutor thursday but ill basically said u told me..

I know im keen perhaps its best to work on the basics first..

[Squall]

ive noticed people who come on the internet and have a pc start to learn more about them by just messing around than they do in a class.....but its the paper that says your qualified...nto your expierience.

[Melissa]

true.. but thats about your computer though and i agree ull learn alot about it by tinkering around although by the looks of it these higher certs your not gonna get by tinkering around since its stuff i wouldnt have a clue on or even know exists you needs hands on expereince and know it inside out

[Grimm]

wow.

ive been sneakin in a little networking during the periods im supposed to be studying hardware and software. i finaly understand it, but im not good with the subnetting.

uhh its stil hard tho...

[Chantelle]

do not worry this question is a little bit extra hard!

if u want any help with anything feel free to ask though, subnetting isnt the easiest of things

[Grimm]

this is it in my terms - which i dont thik are right but idk.

so a network has the host, who is given wutever number of IPs they need. all these IPs are different. but if all the computers on the network wanna go to the internet, they must go thru the host. so a subnet takes the IP and makes it easier for the host to use. so instead of having every IP be different, they can all have the IP address 255.255.255.0 and use the MAC address to adress each computer on the network, so its easier for the host to keep track of them.

i dont think thats right, but thats wut ive gotten out of ciscos terrible learning thing on their site....

[Chantelle]

thats kinda all over the place.. but bits are right

THere can be many hosts or servers on a network.. one which is the gatewat to either the internet or say another network is called a gateway known as default gateway.

So anything outside the normal network forwards it onto the gateway.

the subnet mask is basically what determines which part is the network address and which part is client address.. It also determeins how many clients it supports/ how many subnets are avaialble etc.

I wont go into that though thats extremeely complicated which is what this question was about.

Its better the master the basics first then take it to another level otherwise ull confuse urself badly..

Incidentally a MAC address is just an individual hard coded address for an individual network interface almost liek a serial number. Its useful for certain things.