Hi Sarah, Since all you need is just five usable subnets, the way I go about it is: 2 raise to the power of 3=8 subnets. (You cannot use 2 raise to the power of 2, cos that would give me 4 subnets but I need at least 5 subnets). It means you can not get exactly five subnets, you will have 3 extra subnets for future use. From above you borrowed 3-bits from the last octet of the given IP address for subnet purposes, then going by the last octet the eight bit have these weights (128, 64, 32, 16, 8, 4, 2, 1), since you are using the first three bits then it add up to be 128+64+32=224, now to get the number of IP addresses in each subnet, 256-224=32. It also means your IP addresses would be multiples of 32. The 8 subnets would now be:
1. 65.85.105.0 255.255.255.224 2. 65.85.105.32 255.255.255.224 3. 65.85.105.64 255.255.255.224 4. 65.85.105.96 255.255.255.224 5. 65.85.105.128 255.255.255.224 6. 65.85.105.160 255.255.255.224 7. 65.85.105.192 255.255.255.224 8. 65.85.105.224 255.255.255.224 It is now up to you which five to utilize first. For documentation purposes and ease of troubleshooting, it will be appropriate you use the first five and leave the rest for future development and expansion. Regards Oletu ----- Original Message ----- From: Sarah Parker To: Sent: Thursday, December 13, 2001 8:15 PM Subject: Help with IP Addressing/VLSM- work project [7:29160] > Hello Everyone, > > I am working on a small IP address project and trying > to figure out VLSM. > > Since I am not very good and do not have much > experience with IP addressing, I wanted to send this > to make sure what I have is correct or if I am really > wrong on this one. > Thanks in advance for any feedback or corrections!! > > This is a new network- > Current IP Address=65.85.105.0 > Mask=255.255.255.0 > > I need a total of 5 subnets. > > What I did > Took 65.85.105.0, 255.255.255.128 to subnet into 2 > networks, > This gave me > Subnet 1= 65.85.105.0, hosts 1-126, broadcast 127 > Subnet 2=65.85.105.128, hosts 129-254, broadcast 255 > > Took 65.85,105.128 255.255.255.192 to subnet into 4 > subnets > This gave me > Subnet 1=65.85.105.0. hosts 1-62, broadcast 63 > Subnet 2=65.85.105.64, hosts 54-126, broadcast 127 > Subnet 3=65.85.105.128, hosts 129-190, broadcast 190 > Subnet 4=65.85.105.192, hosts 193.254, broadcast 255 > > So this would give me to use on the network > 1=65.85.105.0 255.255.255.128 (17 mask?) > 2=65.85.105.0 255.255.255.192 (18 mask?) > 3=65.85.105.64 255.255.255.192 > 4=65.85.105.128 255.255.255.192 > 5=65.85.105.192 255.255.255.192 > > > Did I do this correctly? This is based on using subnet > zero. > > I am using a public class A but for security reasons I > did change the actual real address. > > Thanks again for everyones feedback. > > > __________________________________________________ > Do You Yahoo!? > Check out Yahoo! Shopping and Yahoo! Auctions for all of > your unique holiday gifts! Buy at http://shopping.yahoo.com > or bid at http://auctions.yahoo.com _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=29205&t=29160 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
