Appendix B IP Addresses and Subnetting
ES-1552 User’s Guide
156
Subnetting
You can use subnetting to divide one network into multiple sub-networks. In the following
example a network administrator creates two sub-networks to isolate a group of servers from
the rest of the company network for security reasons.
In this example, the company network address is 192.168.1.0. The first three octets of the
address (192.168.1) are the network number, and the remaining octet is the host ID, allowing a
maximum of 2
8
– 2 or 254 possible hosts.
The following figure shows the company network before subnetting.
Figure 96
Subnetting Example: Before Subnetting
You can “borrow” one of the host ID bits to divide the network 192.168.1.0 into two separate
sub-networks. The subnet mask is now 25 bits (255.255.255.128 or /25).
The “borrowed” host ID bit can have a value of either 0 or 1, allowing two subnets;
192.168.1.0 /25 and 192.168.1.128 /25.
The following figure shows the company network after subnetting. There are now two sub-
networks,
A
and
B
.
255.255.255.192
/26
1100 0000
192
255.255.255.224
/27
1110 0000
224
255.255.255.240
/28
1111 0000
240
255.255.255.248
/29
1111 1000
248
255.255.255.252
/30
1111 1100
252
Table 78
Alternative Subnet Mask Notation (continued)
SUBNET MASK
ALTERNATIVE
NOTATION
LAST OCTET
(BINARY)
LAST OCTET
(DECIMAL)
Summary of Contents for ES-1552 - V1.12
Page 2: ......
Page 7: ...Safety Warnings ES 1552 User s Guide 7 ...
Page 8: ...Safety Warnings ES 1552 User s Guide 8 ...
Page 10: ...Contents Overview ES 1552 User s Guide 10 ...
Page 20: ...List of Figures ES 1552 User s Guide 20 ...
Page 24: ...List of Tables ES 1552 User s Guide 24 ...
Page 26: ...26 ...
Page 30: ...Chapter 1 Getting to Know Your Switch ES 1552 User s Guide 30 ...
Page 34: ...Chapter 2 Hardware Installation and Connection ES 1552 User s Guide 34 ...
Page 40: ...Chapter 3 Hardware Overview ES 1552 User s Guide 40 ...
Page 42: ...42 ...
Page 54: ...Chapter 5 System ES 1552 User s Guide 54 ...
Page 58: ...Chapter 6 Port Settings ES 1552 User s Guide 58 ...
Page 70: ...Chapter 10 Mirroring ES 1552 User s Guide 70 ...
Page 86: ...Chapter 13 Layer 2 L2 Management ES 1552 User s Guide 86 ...
Page 88: ...Chapter 14 Cable Diagnostics ES 1552 User s Guide 88 ...
Page 92: ...Chapter 15 Auto Denial of Service DoS ES 1552 User s Guide 92 ...
Page 96: ...96 ...
Page 101: ...Chapter 17 Event Logging ES 1552 User s Guide 101 Figure 55 Searching RAM Flash Logs ...
Page 104: ...Chapter 17 Event Logging ES 1552 User s Guide 104 ...
Page 118: ...Chapter 18 SNMP ES 1552 User s Guide 118 ...
Page 134: ...Chapter 19 RMON Lite ES 1552 User s Guide 134 ...
Page 146: ...Chapter 21 Troubleshooting ES 1552 User s Guide 146 ...
Page 148: ...148 ...
Page 152: ...Appendix A Product Specifications ES 1552 User s Guide 152 ...
Page 164: ...Appendix C Legal Information ES 1552 User s Guide 164 ...