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7.9 Net Range

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By So Hee Park 2 min read

CC by Aru

✅ Net Range

  • From an IP + subnet mask, we can calculate all characteristics of the LAN.
  • Net range = all important addresses inside a network.

✅ Example

  • Host IP:

    • 192.168.10.10/24

☑️ Identifying the Class

  • /24 + beginning with 192

  • Therefore:

    • Class C

✅ Type Address (Dirección Tipo)

☑️ Rule

  • Replace all host bits with X.

☑️ Example

  • /24
  • 24 bits = network
  • 8 bits = host

✔️ Result

  • 192.168.10.XXXXXXXX

✅ Network Address

☑️ Rule

  • Replace all X with 0.

✔️ Result

  • 192.168.10.0/24

☑️ Notes

  • Identifies the network itself.
  • No data should be sent here.

✅ First Host Address

☑️ Rule

  • All host bits = 0
  • Last bit = 1

✔️ Binary

  • XXXXXXXX → 00000001

✔️ Result

  • 192.168.10.1

✅ Last Host Address

☑️ Rule

  • All host bits = 1
  • Last bit = 0

✔️ Binary

  • 11111110

✔️ Result

  • 192.168.10.254/24

✅ Broadcast Address

☑️ Rule

  • Replace all X with 1.

✔️ Result

  • 192.168.10.255/24

☑️ Purpose

  • Sending to broadcast IP sends message to all devices in network.

✅ Multicast Reminder

  • Multicast requires:

    • Class D IPs
    • receiving hosts configured for multicast

✅ Example: Host 72

☑️ Binary Conversion

  • 64 + 8 = 72

  • Binary:

    • 01001000

✔️ Result

  • 192.168.10.72

✅ Full Example of Address Range

☑️ Given IP

  • 172.23.84.138/16

✅ IP Address

☑️ Binary

  • 10101100
  • 00010111
  • 01010100
  • 10001010

☑️ Decimal

  • 172.23.84.138/16

✅ Subnet Mask

☑️ Binary

  • 11111111
  • 11111111
  • 00000000
  • 00000000

☑️ Decimal

  • 255.255.0.0/16

✅ Type Address

☑️ Binary

  • 10101100
  • 00010111
  • xxxxxxxx
  • xxxxxxxx

☑️ Decimal

  • 172.23.xxxxxxxx.xxxxxxxx/16

✅ Network Address

☑️ Binary

  • 10101100
  • 00010111
  • 00000000
  • 00000000

☑️ Decimal

  • 172.23.0.0/16

✅ First Host Address

☑️ Binary

  • 10101100
  • 00010111
  • 00000000
  • 00000001

☑️ Decimal

  • 172.23.0.1/16

✅ Last Host Address

☑️ Binary

  • 10101100
  • 00010111
  • 11111111
  • 11111110

☑️ Decimal

  • 172.23.255.254/16

✅ This Host Address

☑️ Decimal

  • 172.23.84.138/16

✅ Broadcast Address

☑️ Binary

  • 10101100
  • 00010111
  • 11111111
  • 11111111

☑️ Decimal

  • 172.23.255.255/16

✅ Standard vs Non-Standard Prefixes

☑️ Standard Prefixes

  • /8
  • /16
  • /24

☑️ Non-Standard Prefixes

  • More complicated.
  • Use subnetting.

☑️ Subnetting

  • Dividing a network into smaller groups/subnets.

✅ How to See Your IP?

☑️ Subnetting Identification

  • Weird/non-standard masks usually indicate subnetting.

✅ Checking Private IP in Windows 10

☑️ Method 1

✔️ Steps

  • Control Panel
  • Network and Internet
  • Network and Sharing Center
  • Active Network
  • Details

☑️ Method 2

✔️ Steps

  • Windows + R
  • cmd
  • ipconfig

✅ Important Class Example

  • If classroom internet fails:

    • nearby classroom may fail too

  • Reason:

    • both may belong to same subnet.

✅ Checking Private IP in Linux

☑️ Commands

✔️ Install Tools

  • sudo apt-get install net-tools

✔️ Show IP

  • ifconfig

✅ Public IP

☑️ Meaning

  • IP seen by other people/devices on the internet.

☑️ Usually Given By

  • Proxy
  • Router (if no proxy)

☑️ Location

  • Usually points to ISP technical office location.

✅ Public IP Websites

  • https://vermiip.es/
  • https://whatismyipaddress.com/es/mi-ip

✅ Checking if an IP is Accessible

☑️ Command

  • ping

☑️ Example

  • ping 8.8.8.8

☑️ Notes

  • 8.8.8.8 = Google DNS server.
  • Big companies usually have fixed DNS servers.

✅ Ping and ICMP

☑️ Ping Uses

  • ICMP protocol.

☑️ Purpose

  • Check if destination is reachable.

✅ Connection Quality

☑️ Measured Using

  • Response time.
  • TTL (Time To Live).

☑️ Better Connection

  • Lower response time compared to TTL.

☑️ Packet Loss

  • Ideal:

    • 0%

  • Acceptable:

    • 20–30%
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