Hello,
I am a little fuzzy on vlsm for class A and B addresses so I thought I'd try to get some clarification with an example.
Here's the example requirement.
Network address = 172.16.0.0 Net A 2500 hosts Net B 1300 hosts Net C 400 hosts Wan Links 2 hosts
Would I use the following masks?
Net A 2500 hosts = 172.16.0.1/20 -> 172.16.15.254/20 4094 usable hosts Net B 1300 hosts = 172.16.16.1/21-> 172.16.23.254/21 2046 usable hosts Net C 400 hosts /23 172.16.24.1/23 -> 172.16.25.254/23 512 usable hosts
Wan Link A 172.16.26.1/30 -> 172.16.26.2/30 Wan Link B 172.16.26.5/30 -> 172.16.26.6/30
If this is correct ( I suspect it isn't) it still seems to "waist" quite a few addresses (Net A has 4094 possible but only requires 2500). All the examples I've seen have used class C addresses so I start to get really confused going to larger networks.
Also, has anybody had the CCNA throw class B vlsm questions at you or do they stick to the class c addresses? How about the CCNP?
Thanks for your help.
Dan Cox