Help with IPv4 subnet addresses

MLE

Can someone please explain how to figure out which IPv4 subnetted address represent valid host address?
Choose three. Just not sure how to work the problem to get the correct answer thanks.

a.) 172.16.4.127/26
b.) 172.16.4.155/26
c.) 172.16.4.193/26
d.) 172.16.4.95/27
e.) 172.16.4.159/27
f.) 172.16.4.207/27

networker050184

Do you know how to find the network address? Broadcast address? Everything in between is a valid host address.

mguilmot

/26 =11111111.11111111.11111111.11000000 => Final 1 with following 0's= 1000000 = 64 as increment
[FONT=Times New Roman, serif]172.16.4.0-63[/FONT]
[FONT=Times New Roman, serif]172.16.4.[/FONT]64-127
[FONT=Times New Roman, serif]172.16.4.[/FONT]128-191
[FONT=Times New Roman, serif]172.16.4.[/FONT]192-255


/27 =11111111.11111111.11111111.11100000 => Final 1 with following 0's= 100000 = 32 as increment
[FONT=Times New Roman, serif]172.16.4.[/FONT]0-31
[FONT=Times New Roman, serif]172.16.4.[/FONT]32-63
[FONT=Times New Roman, serif]172.16.4.[/FONT]64-95
[FONT=Times New Roman, serif]172.16.4.[/FONT]96-127
[FONT=Times New Roman, serif]172.16.4.[/FONT]128-159
[FONT=Times New Roman, serif]172.16.4.[/FONT]160-191
[FONT=Times New Roman, serif]172.16.4.[/FONT]192-223
[FONT=Times New Roman, serif]172.16.4.[/FONT]224-255


You cannot use the first, nor the lastaddress in these ranges. So, only 3 are correct

fadhil

take an ip address AND with subnet mask, result address will be a network address. From a subnet mask you can know a block size of that network address. as you know that know that a network address and broadcast address is not valid host so between them(network address and broadcast address) valid hosts are available.

Ltat42a

Here's an example of ANDing....

MLE

Thanks you all for your input and help. I wasn't aware I couldnt use the first, nor the lastaddress in the ranges.