Figure 182 subnetting example: after subnetting, Table 133 subnet 1, Example: four subnets – ZyXEL Communications GS-2750 User Manual
Page 315
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Appendix A IP Addresses and Subnetting
GS-2750 User’s Guide
315
Figure 182 Subnetting Example: After Subnetting
In a 25-bit subnet the host ID has 7 bits, so each sub-network has a maximum of 2
7
– 2 or 126
possible hosts (a host ID of all zeroes is the subnet’s address itself, all ones is the subnet’s
broadcast address).
192.168.1.0 with mask 255.255.255.128 is subnet A itself, and 192.168.1.127 with mask
255.255.255.128 is its broadcast address. Therefore, the lowest IP address that can be assigned
to an actual host for subnet A is 192.168.1.1 and the highest is 192.168.1.126.
Similarly, the host ID range for subnet B is 192.168.1.129 to 192.168.1.254.
Example: Four Subnets
The previous example illustrated using a 25-bit subnet mask to divide a 24-bit address into two
subnets. Similarly, to divide a 24-bit address into four subnets, you need to “borrow” two host
ID bits to give four possible combinations (00, 01, 10 and 11). The subnet mask is 26 bits
(11111111.11111111.11111111.11000000) or 255.255.255.192.
Each subnet contains 6 host ID bits, giving 2
6
- 2 or 62 hosts for each subnet (a host ID of all
zeroes is the subnet itself, all ones is the subnet’s broadcast address).
Table 133 Subnet 1
IP/SUBNET MASK
NETWORK NUMBER
LAST OCTET BIT
VALUE
IP Address (Decimal)
192.168.1.
0
IP Address (Binary)
11000000.10101000.00000001.
00000000
Subnet Mask (Binary)
11111111.11111111.11111111.
11000000
Subnet Address:
192.168.1.0
Lowest Host ID: 192.168.1.1
Broadcast Address:
192.168.1.63
Highest Host ID: 192.168.1.62
- ZyXEL Dimension GS-1116A
- ZyXEL Dimension ES-2108PWR
- DIMENSION ES-4024
- MI-7526F
- ZyXEL Dimension ES-2048
- DIMENSION ES-1016A
- ONU-6040B-21
- HOMEBOUND TRIPLE PLAY DELIVERY ES-315-F
- IES-708-22
- Version 1.03
- ZyXEL Dimension ES-1552
- ES-2108
- ES-2108
- ZyXEL Dimension ES-1124
- 2-Slot 10GBase-CX4 10Gigabit Module EM-412
- GS-105B/108B
- ES-4024A
- ETHERNET SWITCHES ES-1016
- GS-4012F/4024
- ZyXEL Dimension ES-2024
- ZyXEL Dimension ES-2108
- ZyXEL Dimension GS-3012F
- VES-1000
- PoE-80
- ES-1124
- 4500 Series
- ES-3148 Series
- GS-3012F Series
- Ethernet-to-Fiber Media Converter MC1000-SFP-FP
- GS2200-24P
- ES-105A/108A
- ZyXEL Dimension GS-1016
- EES-1024AF
- GS-4012
- IES-6000
- ES-315
- ES-2108 Series
- ZyXEL Dimension ES-2024PWR
- GS-3012F/3012
- GS-108B
- GS-105
- GS-4012F
- VES-1616
- A-6000
- LAYER 3 ES-3124
- GS-105A
- MGS-3712F
- ZyXEL Dimension GS-108A
- MES-2110
- EXTRASMART ES-1552
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- IES-1248-51V
- GS-2724
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- VDSL SWITCH VES-1616F-3X
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- ZyXEL Dimension ES-3124-4F
- ES-2024 Series
- NetAtlas Workgroup
- PLA470 Series
- GS-1548
- ES-3124PWR
- P-660H-Tx v2
- ZyXEL Dimension ES-3148
- ZyXEL P-872H
- ZyXEL Dimension ES-2108-F
- ZyXEL Dimension ES-3024
- XGS-4728F
- XGS-4528F
- ZyXEL Dimension ES-1528
- ES-3124
- ISTACKING ES-2108
- PES-1014
- ZyXEL Ethernet Switches
- BPS-120
- GS-3012
- ZyXEL Dimension ES-4024
- ZYAIR B-4000
- ES-105/ES-108