Subnet problem

[Destroyer^]

Hey guys just having a bit of a problem with part of subnetting, im doing a CCNA course at the moment wondered if i could have a hand...

now this question is give me a headache... 10.102.4.56 / subnet mask 255.252.0.0
10.104.100.12 / 255.252.0.0
10.106.4.57/255.252.0.0
10.108.100.13/255.252.0.0
find out which 2 are on the same network

now i know this is a class A network and it uses 5 bits from the 2nd octet giving it a /14 prefix
i have four addresses including this one to find two that are on the same network... i usually do an AND calculation of the first network address

this gives me 10.100.0.0 Network and because of the 6 bits borrowed from the host leaving 2 2^2 = 8

that gives 8 hosts per subnet meaning it should go up in 100 - 108 109 - 116 117 - 124 but given that then it would mean that they all are on the same network?

can any1 shed some light

[badass]

Hey guys just having a bit of a problem with part of subnetting, im doing a CCNA course at the moment wondered if i could have a hand...

now this question is give me a headache... 10.102.4.56 / subnet mask 255.252.0.0
10.104.100.12 / 255.252.0.0
10.106.4.57/255.252.0.0
10.108.100.13/255.252.0.0
find out which 2 are on the same network

now i know this is a class A network and it uses 5 bits from the 2nd octet giving it a /14 prefix
i have four addresses including this one to find two that are on the same network... i usually do an AND calculation of the first network address

this gives me 10.100.0.0 Network and because of the 6 bits borrowed from the host leaving 2 2^2 = 8

that gives 8 hosts per subnet meaning it should go up in 100 - 108 109 - 116 117 - 124 but given that then it would mean that they all are on the same network?

can any1 shed some light

6 bits from the second octet.

None of the IPA's listed there by you are in the same network.
Also, you are over complicating it. Forget the hosts per subnet. It's confusing you. There are in fact 262142 possible hosts per subnet.

Follow the technique taught by your course to solve this

Finally, that is a rubbish question if they are asking you that. One with suck a large host part of teh address never comes up in both the CCNA exam nor in real life. The shartest subnet mask I have seen in production that was actually used for a network was 16 bits.

[Destroyer^]

oh really... well these are not in my course i just am using some questions as revision as i have exams from 18th jan and just wanted to make sure i could subnet properly... the teacher we have at University isnt that great tbh with explaining subnetting with questions... hmm yeah well i couldnt remeber if it would be just using the 2 bits not used of that octet or the whole host being the other 16 also but nm...

[cantthinkof1]

oh really... well these are not in my course i just am using some questions as revision as i have exams from 18th jan and just wanted to make sure i could subnet properly... the teacher we have at University isnt that great tbh with explaining subnetting with questions... hmm yeah well i couldnt remeber if it would be just using the 2 bits not used of that octet or the whole host being the other 16 also but nm...

I agree with the other poster. I have just completed a networking fundamentals course that was Cisco based. All the subnetting was /24 or more typically /26 /28.

To be on the same network the IP addresses have to be the same i.e. 10.10.10.xxx or 192.168.1.xxx

There are some good subnetting examples in the subnetting exercises in the Cisco notes.

Feel free to bounce a few questions off me if it helps. I have an exam on 9th January.

Good Luck with yours