4 Replies Latest reply: Jun 19, 2015 11:55 PM by Conwyn RSS

    I need to find three subnets in a B class network with a C class custom netmask.



      I'm studying for CCT and during our subnetworks classes, I have a teacher who asked us a difficult question and I'm really having a hard time getting the answer to it. Please help me.

      So here I go:

      I have this ip: / 26 and I'm required to divide this netspace into 3 subnets of my choosing in regards to the following request: one of the subnets requires 20 stations, another needs to have 10 and another one needs to have 12 stations.


      So considering I have a B class netspace that looks like this after prefixing it : 141.25.137. (11xxxxxx) this last byte is in binary.

      I applied the formula 2^3rd power - 2 = 6 subnets  (I needed only 3 so the remaining 3 are future developing). I couldn't go only 2^2nd power because I couldn't cram 3 subnets into 4 -2 zone.


      So alas, this is what I came up with: 141.25.137.(11111xxx) / 29 . The wildcards here are only 2^3 = 8 and I can't have the required stations in each subnet.


      Please tell me what to do.