Appendix D IP Addresses and Subnetting
Vantage CNM User’s Guide
645
By convention, subnet masks always consist of a continuous sequence of ones
beginning from the leftmost bit of the mask, followed by a continuous sequence of
zeros, for a total number of 32 bits.
Subnet masks can be referred to by the size of the network number part (the bits
with a “1” value). For example, an “8-bit mask” means that the first 8 bits of the
mask are ones and the remaining 24 bits are zeroes.
Subnet masks are expressed in dotted decimal notation just like IP addresses. The
following examples show the binary and decimal notation for 8-bit, 16-bit, 24-bit
and 29-bit subnet masks.
Network Size
The size of the network number determines the maximum number of possible
hosts you can have on your network. The larger the number of network number
bits, the smaller the number of remaining host ID bits.
An IP address with host IDs of all zeros is the IP address of the network
(192.168.1.0 with a 24-bit subnet mask, for example). An IP address with host
IDs of all ones is the broadcast address for that network (192.168.1.255 with a
24-bit subnet mask, for example).
As these two IP addresses cannot be used for individual hosts, calculate the
maximum number of possible hosts in a network as follows:
Table 283
Subnet Masks
BINARY
DECIMAL
1ST
OCTET
2ND
OCTET
3RD
OCTET
4TH
OCTET
8-bit mask
11111111
00000000
00000000
00000000
255.0.0.0
16-bit mask
11111111
11111111
00000000
00000000
255.255.0.0
24-bit mask
11111111
11111111
11111111
00000000
255.255.255.0
29-bit mask
11111111
11111111
11111111
11111000
255.255.255.248
Table 284
Maximum Host Numbers
SUBNET MASK
HOST ID SIZE
MAXIMUM NUMBER OF
HOSTS
8 bits
255.0.0.0
24 bits
2
24
– 2
16777214
16 bits
255.255.0.0
16 bits
2
16
– 2
65534
24 bits
255.255.255.0
8 bits
2
8
– 2
254
29 bits
255.255.255.248
3 bits
2
3
– 2
6
Summary of Contents for VANTAGE CNM
Page 2: ......
Page 20: ...New Template User s Guide 20...
Page 23: ...23 PART I Introduction Introducing Vantage CNM 21 GUI Introduction 25...
Page 24: ...24...
Page 46: ...46...
Page 50: ...Chapter 3 Load or Save Building Blocks BB Vantage CNM User s Guide 50...
Page 140: ...Chapter 6 Device Security Settings Vantage CNM User s Guide 140 IKE Gateway Policy Add Edit...
Page 242: ...Chapter 8 Device Log Vantage CNM User s Guide 242...
Page 246: ...246...
Page 346: ...Chapter 11 IPSec VPN Vantage CNM User s Guide 346...
Page 356: ...Chapter 13 L2TP VPN Vantage CNM User s Guide 356...
Page 384: ...Chapter 14 Vantage CNM User s Guide 384...
Page 408: ...408...
Page 456: ...Chapter 18 Firmware Management Vantage CNM User s Guide 456...
Page 474: ...474...
Page 494: ...494...
Page 534: ...Chapter 26 Device Alarm Vantage CNM User s Guide 534...
Page 535: ...535 PART VII Log Report Device Operation Report 537 CNM Logs 553 VRPT 555...
Page 536: ...536...
Page 552: ...Chapter 27 Device Operation Report Vantage CNM User s Guide 552...
Page 560: ...560...
Page 580: ...Chapter 30 CNM System Setting Vantage CNM User s Guide 580...
Page 588: ...Chapter 33 Vantage CNM Software Upgrade Vantage CNM User s Guide 588...
Page 592: ...Chapter 35 About CNM Vantage CNM User s Guide 592...
Page 593: ...593 PART IX Account Management User Group 595 Account 599...
Page 594: ...594...
Page 598: ...Chapter 36 User Group Vantage CNM User s Guide 598...
Page 603: ...603 PART X Troubleshooting Troubleshooting 605...
Page 604: ...604...
Page 610: ...610...
Page 616: ...Appendix A Product Specifications Vantage CNM User s Guide 616...
Page 634: ...Appendix B Setting up Your Computer s IP Address Vantage CNM User s Guide 634...
Page 656: ...Appendix E IP Address Assignment Conflicts Vantage CNM User s Guide 656...
Page 666: ...Appendix G Importing Certificates Vantage CNM User s Guide 666...