A table has four columns: C I D R notation; Netmask notation; Nodes, can’t use all O S or all 1 s; and Description. The row entries are as follows. Row 1: C I D R notation, forward slash 0. Netmask notation, 0.0.0.0. Nodes, can’t use all 0 s or all 1 s, 4,294,967,294. Description, Entire Internet. Row 2: C I D R notation, forward slash 8. Netmask notation, 255.0.0.0. Nodes, can’t use all 0 s or all 1 s, 16,777,214. Description, Class A. Row 3: C I D R notation, forward slash 16. Netmask notation, 255.255.0.0. Nodes, can’t use all 0 s or all 1 s, 65,534. Description, Class B. Row 4: C I D R notation, forward slash 24. Netmask notation, 255.255.255.0. Nodes, can’t use all 0 s or all 1 s, 254. Description, Class C. Row 5: C I D R notation, forward slash 25. Netmask notation, 255.255.255.128. Nodes, can’t use all 0 s or all 1s, 126. Description, no data. Row 6: C I D R notation, forward slash 26. Netmask notation, 255.255.255.192. Nodes, can’t use all 0 s or all 1 s, 62. Description, no data. Row 7: C I D R notation, forward slash 27. Netmask notation, 255.255.255.224. Nodes, can’t use all 0 s or all 1 s, 30. Description, no data. Row 8: forward slash 28. Netmask notation, 255.255.255.240. Nodes, can’t use all 0 s or all 1 s-, 14. Description, no data. Row 9: C I D R notation, forward slash 29. Netmask notation, 255.255.255.248. Nodes, can’t use all 0 s or all 1 s, 6. Description, no data. Row 10: C I D R notation, forward slash 30. Netmask notation, 255.255.255.252. Nodes, can’t use all 0 s or all 1 s, 2. Description, no data.

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IP Addressing Primer

APPENDIX B

Many organizations need more flexibility to define logical groups of nodes within a LAN. There are many reasons to create subsets of LANs, or subnets. These reasons include:

  • Separate network segments that use different technologies—Subnets allow Ethernet, wireless, and other LAN technologies to have groups of addresses within the organization’s address space.
  • Create security groups—Subnets make it easy to logically group nodes by functional use or type of access needed. This feature allows security administrators to limit permissions to nodes within a particular subnet address ...

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