| reply to connellyg
Re: [Other] Help Subnetting? CISCO! CCNA Would it not have been easier to stay in class and get ppl here to help, than sit at home by yourself trying to do it?
Anyway... 192.183.10.0
You cant have 80 subnets on that address because if you were to work it out it would mean you would have to use 7 bits for subnetting which would leave you with 1 bit for hosts, which is impossible. So i'll work it out with 25 subnets.
You need 25 subnets, so you would do.. 2 to the power of whatever til you reached the number you need. So we would need to do, 2 to the power of 5, which is 32... thats more than you need.
so because you have borrowed 5 bits that would leave 3 bits for hosts.
128 64 32 16 8 4 2 1
The bits in bold is what is used for subnetting... add those together to get your subnet mask.. which is 248.. the full subnet mask would be 255.255.255.248
to work out max subnets you would do 2 to the power of 5.. which is 32. To work out useable hosts you would take off 2.
The same thing goes for hosts... 2 to the power of 3 which is 8. Take off 2 to get the useable amount.
because the last bit in the subnet mask ends at 8.. every subnet address will be a multiple of 8.
so the 1st USEABLE subnet would be 192.183.10.8 the broadcast for that would be 192.183.10.15 The reason being.. 9 - 14 are useable hosts. 15 is the broadcast and 16 would be the NEXT subnet.
Let me know if you need any more help.
Regards.
Lee |
