I need help I don't understand class B ip address. I was assigned an IP address of 172.16.0.0 with a subnet mask of 255.255.224.0. There are three location San Diego as the headquarters with an administation department of 30 workstation, a Sales department with 25 and the marketing department 15 workstations. The Chicago, IL location has 30 workstation for the Administation and the R&D department and a Sales department of have 25 workstations each. The last location Birmingham, AL has 30 workstations for Administraion, R&D and Sales department . I'm having a really hard time subnetting this IP address. Can someone help me!!!. Any help will be much appreciated.

Sounds like a re-hashed homework question. I would have thought that anyone with the responsibility of such a complex network would already know about sub-neting or at least know where to find the information. http://www.ralphb.net/IPSubnet/ Stuart

If you have a subnet mask of 255.255.255.224.0 this is meant you have 2^3-2 = 6 subnets x.x.x.1110.0000 your subnet mask so we know that we can make 6 subnets with this subnet mask. x.x.x.001 0.0000 x.x.x.010 0.0000 x.x.x.011 0.0000 x.x.x.100 0.0000 x.x.x.101 0.0000 x.x.x.110 0.0000 Each subnet could contain 30 hosts. We can conclude the following settings: 3 subnets for San Diego, 2 subnets for Chicago, 1 subnet for Birmingham. See below the sub-netting for San Diego: Administration: 172.16.32.0 Sales: 172.16.64.0 Marketing: 172.16.96.0 See below the sub-netting for Chicago: Administration: 172.16.128.0 Sales + R&D: 172.16.160.0 See below the sub-netting for Birmingham: Administration + Sales + R&D: 172.16.192.0 Hope that help you. Nicobrown

You can do it on paper or get solarwinds calculator. I read it wrong and answer it wrong too. So get off my case you goober.

I'm fairly sure thats the Cisco CCNA3 case study. You need to have Subnetting burned into your brain in order to proceed any further with the CCNA so you should seek advise at your college/uni on how to do it. D.