DHCP Option 43 Generator

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DHCP Option 43 Generator

Generate vendor-specific DHCP options for TFTP servers, vendor class identifiers, and custom configurations

Option 43 Configuration Generator

Select Vendor

Convert Option 43 Hex to IP Address

Supports Cisco formats (f1xxx, f2xxx, f3xxx) and standard TFTP format (0104). Cisco format: f1 + length + hex IP(s) where length = number_of_IPs × 4

About DHCP Option 43

DHCP Option 43 is a vendor-specific option that allows DHCP servers to provide vendor-specific information to DHCP clients. This is commonly used for TFTP server addresses, vendor class identifiers, and other vendor-specific configuration parameters.

Reference: This implementation follows Cisco's official DHCP Option 43 specification for lightweight access points and Wi-Fi 7 APs.

Common Use Cases:
  • TFTP Server Addresses: Provide IP addresses of TFTP servers for firmware updates
  • Vendor Class Identifiers: Identify specific vendor equipment types
  • Custom Configuration: Vendor-specific parameters and settings
  • Network Services: Point devices to specific network services
Cisco-Specific Methods:
Multiple WLC Format Specification:

Single WLC: f104 + hexIP (f1 + length 4 + IP)

Multiple WLCs: f108 + hexIP1 + hexIP2 (f1 + length 8 + IP1 + IP2)

Length Calculation: number_of_IPs × 4 (e.g., 2 IPs = length 8, 3 IPs = length 12)

Example: For IPs 192.168.1.10 and 192.168.1.11: f108C0A8010AC0A8010B

  • WLC Provisioning (f1xxx): Classic method for lightweight access points to join Wireless LAN Controllers
  • Multiple WLC Provisioning: Support for multiple WLC IP addresses for redundancy and load balancing. Format: f1 + length + hexIP1 + hexIP2 + ... (length = number_of_IPs * 4)
  • EWC Conversion (f2xxx): Embedded Wireless Controller conversion method for integrated solutions
  • Multiple EWC Conversion: Support for multiple EWC IP addresses for redundancy. Format: f2 + length + hexIP1 + hexIP2 + ... (length = number_of_IPs * 4)
  • Catalyst to Meraki Migration (f3xxx): Fast offline migration from Catalyst switches to Meraki cloud-managed devices
  • Multiple Catalyst to Meraki Migration: Support for multiple Meraki IP addresses for redundancy. Format: f3 + length + hexIP1 + hexIP2 + ... (length = number_of_IPs * 4)
Wi-Fi 7 AP Support:
  • Global Use APs (GUAPO): Support for Wi-Fi 7 access points including CW9178, CW9176, CW9178I, CW9176I, CW9176D1, CW9172I, CW9172H
  • Same Format: Wi-Fi 7 APs use the same Option 43 format as traditional lightweight access points
  • Vendor Class Identifiers: Specific VCI values for different Wi-Fi 7 AP models as documented in Cisco's official specification

Common Examples

Cisco TFTP Server: 192.168.1.100 → Option 43: 0104C0A80164
Cisco WLC Provisioning: 192.168.1.100 → Option 43: f104C0A80164
Cisco Multiple WLC: 192.168.1.100, 192.168.1.101 → Option 43: f108C0A80164C0A80165
Cisco EWC Conversion: 10.0.0.50 → Option 43: f2040A000032
Cisco Multiple EWC: 10.0.0.50, 10.0.0.51 → Option 43: f2080A0000320A000033
Cisco Catalyst to Meraki: 172.16.0.10 → Option 43: f304AC10000A
Cisco Multiple Catalyst to Meraki: 172.16.0.10, 172.16.0.11 → Option 43: f308AC10000AAC10000B
Avaya TFTP Server: 10.0.0.50 → Option 43: 01040A000032
Polycom TFTP Server: 172.16.0.10 → Option 43: 0104AC10000A