A detail about VLSM
totts
Member Posts: 117
in CCNA & CCENT
I was a bit surprised about this so I thought I'd post it in case others thought the same. I may be at risk of saying something that everyone knows about but anyway...
If a network has say the following addresses in it... 172.16.1.1/24 172.16.2.2/24 and 10.1.1.1/255.255.240 it doesn't necessarily mean that VLSM is being used. The detail is that VLSM implies that the different masks are in use in the same A, B or C class, so using the above example if one of the 24 bit masks was differenet in the class B 172 address, then VLSM would be in use.
If a network has say the following addresses in it... 172.16.1.1/24 172.16.2.2/24 and 10.1.1.1/255.255.240 it doesn't necessarily mean that VLSM is being used. The detail is that VLSM implies that the different masks are in use in the same A, B or C class, so using the above example if one of the 24 bit masks was differenet in the class B 172 address, then VLSM would be in use.
totts from essex
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r_durant
Member Posts: 486 ■■■□□□□□□□
Yup, I came across a question similar to that in one of the books I'm reading...
I think there's a trick about things like that to throw you off, because you see the different subnets and would be drawn to believe it's VLSM....
Cheers...CCNA (Expired...), MCSE, CWNA, BSc Computer Science
Working on renewing CCNA! -
totts
Member Posts: 117
:P ah at least I'm not alone! I was beginning to think that I was trying to convince people that black was black! Yes I agree its one to watch... it would be easy to say that VSLM was in operation, but it may not be. You have to watch out for that 'class' detail!totts from essex