Help answer this question.

[rphann]

This question is from the Microsoft Training Kit.

For each address block and internally configured subnet mask, determine the number of available subnets and hosts per subnet.

Original Address Block: 208.147.66.0 /25
Internal Configured Subnet Mask: 255.255.255.248
Number of Available Subnets:
Number of Available Hosts per Subnet:

My answers are 16 for Number of Available Subnets and 6 for Number of Available Hosts per Subnet. Although the answers shown in the Training Kit, shows 8 for Number of Available Subnets and 6 for Number of Available Hosts per Subnet. Please let me know which one is the correct answer.

Thanks,
rphann

[mikedisd2]

If it's reserved 5x bits for the subnet, I would have thought that gave 32x subnets with 2^8-2 hosts.

Subnetting isn't my strong point though.

[breaker]

Edit

http://support.microsoft.com/kb/917983

Page 2-66: Number of available subnets incorrect
On page 2-66, in Lesson 3, Practice, Exercise 2 answer block, the last line reads:

"208.147.66.0/25 255.255.255.248 8 6"

It should read:

"208.147.66.0/25 255.255.255.248 16 6"

[mikedisd2]

Bugger, I knew I sucked at subnetting.

[breaker]

If it's reserved 5x bits for the subnet, I would have thought that gave 32x subnets with 2^8-2 hosts.

Subnetting isn't my strong point though.

If the mask is /25 then it leaves you with 7 bits

the new internal mask of 248 is /29

so your are using 4 for network and 3 for host

2^4 = 16
and
2^3-2 = 6

[rphann]

Thanks, Breaker.

So my answer is correct. Thanks for clarifying this for me.

rphann