09-24-2011, 09:11 PM
Dudes please.
255.255.254.0 gives you 2 3rd octet addresses. the first pair is 0- 1.2-3.4-5.
Even # 3rd octet can use the x.x.even.255 for a host, and x.x.odd.o for a host.
Odd 254s/23s have a broadcast address at 255.
if it isn't a reserved address and meets these criteria, you are correct.
Usually I figure out how many networks there are. Then I divide the whatever octet by that number to get my network address closest to my target.
There are only 128,64,32,8,4,2,1,0 per octet. 32 and 64 might get tricky, but that's just 4 and 8 possible networks. If it is beyond midpoint of 64 128 190 255, it's easy to figure out if it is +/- 32 away. 101 is closer to 128-32 than it is to 64(boundary 96=32+64)
Blamo.
128 is over/under, and if I can't divide a 3 digit number by 8 in my head I should do something else.
Don't forget, the reason we don't base everything off 256 is because 0 is a number not a void. anything that hits on a boundary(32 64 96 128 etc in this case) is really hitting the first number of the next network because of the 0(33rd,65th,97th,129th) available address.. And just before that is the broadcast. Broad cast is actually the 32nd address but is numbered 31.
Oh, so masks make sense now... Where is the start of a network? The number of the last network number is where you start The actual 32nd address is what you are looking for, 31.
Only bad thing about google is it won't work when your network can't get to the internet. If you need a tool Boson is a good one.
I can't and on my fingers, too many steps, but I can nail an ip subnet zero network faster than I can find and open a calculator.
255.255.254.0 gives you 2 3rd octet addresses. the first pair is 0- 1.2-3.4-5.
Even # 3rd octet can use the x.x.even.255 for a host, and x.x.odd.o for a host.
Odd 254s/23s have a broadcast address at 255.
if it isn't a reserved address and meets these criteria, you are correct.
Usually I figure out how many networks there are. Then I divide the whatever octet by that number to get my network address closest to my target.
There are only 128,64,32,8,4,2,1,0 per octet. 32 and 64 might get tricky, but that's just 4 and 8 possible networks. If it is beyond midpoint of 64 128 190 255, it's easy to figure out if it is +/- 32 away. 101 is closer to 128-32 than it is to 64(boundary 96=32+64)
Blamo.
128 is over/under, and if I can't divide a 3 digit number by 8 in my head I should do something else.
Don't forget, the reason we don't base everything off 256 is because 0 is a number not a void. anything that hits on a boundary(32 64 96 128 etc in this case) is really hitting the first number of the next network because of the 0(33rd,65th,97th,129th) available address.. And just before that is the broadcast. Broad cast is actually the 32nd address but is numbered 31.
Oh, so masks make sense now... Where is the start of a network? The number of the last network number is where you start The actual 32nd address is what you are looking for, 31.
Only bad thing about google is it won't work when your network can't get to the internet. If you need a tool Boson is a good one.
I can't and on my fingers, too many steps, but I can nail an ip subnet zero network faster than I can find and open a calculator.