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@benis_redux

How many usable host addresses are on the network192.168.8.128/28 and what is its broadcast address

@benis_redux @benis_redux 14 addresses, and the broadcast is 192.168.8.143.

Reasoning a /28 has 16 addresses avaliable in the but the first one 128 goes to the network, the last one 143 is the broadcast. so 192.168.8.129-142 is the usable range.

How you find out how many address there are in a CIDR.

An IPv4 address is 32 bits
00000000 00000000 00000000 00000000

A /28 CIDR implies that the network gets 28 bits out of the 32, so the host bits are 4 bits. You could express the mask in binary like so.

11111111 11111111 11111111 11110000 in the case of the network
or
00000000 00000000 00000000 00001111 in the case of the hosts

Focusing on the last octet 00001111

That number in binary is 16. A quick way to calculate that number is you know that four bits are going to the hosts so you can do 2⁴ which equals 16, you always minus two off the end result for network and broadcast address which is why it's 14. You can apply this logic for the remainder of calculating CIDR addresses. And they will have you doing this in the CCNA exam.

@benis_redux I typed six bits but meant four.

@benis_redux Oh yeah and I guess I forgot to say what that subnet is. It's 255.255.255.240

How you find that is again with the last octet.

11110000

An easy way to figure this out would but to understand the following

10000000 = 128
01000000 = 64
00100000 = 32
00010000 = 16
00001000 = 8
00000100 = 4
00000010 = 2
00000001 = 1
00000000 = 0

So for 11110000 you can just add the following

10000000 = 128
+
01000000 = 64
+
00100000 = 32
+
00010000 = 16
==
11110000 = 240

Which is how you get 255.255.255.240 from /28

The subnet mask in binary is
11111111 11111111 11111111 11110000

@sjb I forgor the sauce age, because I remember I had venison in yhe freezer.

@splitshockvirus I suppose meat you shoot yourself is the least processed meat.

@sjb

Even more, my roommates have like 50 lbs of hog I helped raised, and my neighbor has chicken (eggs).

I did get a gallon of orange juice for $12.

@splitshockvirus But you can get oragne juice by milking the chicken.