USG FLEX 700H DHCP Server: Issuing DHCP Option 24 for VOIP Equipment

Zyxel_Kevin

USG FLEX 700H DHCP Server: Issuing DHCP Option 24 for VOIP Equipment

As part of a recent POC (Proof of Concept) for VOIP integration, questions arose regarding the capability of the USG FLEX 700H DHCP server to issue DHCP option 24 to VOIP equipment. This functionality is crucial for VOIP devices to automatically retrieve configuration files from an internal server.

Is it possible for USG FLEX 700H DHCP Server to issue DHCP Option 24?

Yes, the USG FLEX 700H DHCP server can issue DHCP option 24. This functionality has been verified.

How to configure and verify DHCP Option 24?

• Server Configuration:

  • On the USG FLEX 700H, you must first configure a user-defined DHCP option for option 24.
  • The server will then be prepared to respond if a client requests this option.

• Client Request:

  • The client (VOIP equipment) must include option 24 in its DHCP option 55 request list.
  • If the client's request contains option 24, the server will provide it.

• Verification Method:

  • This can be verified by simulating a client (e.g., using a CentOS machine) to request option 24 within its option 55 list.
  • Observing the DHCP server's response through packet capture will confirm if option 24 is being issued.

Example Configuration & Interaction

• DHCP Server Settings:

  • The DHCP server on the USG FLEX 700H should be configured with a user-defined DHCP option for option 24.

• Client Request Flow:

  • A client's DHCP request (specifically within option 55) must explicitly include option 24.

• Server Response:

  • Upon receiving a valid client request, the USG FLEX 700H DHCP server will respond by providing option 24.

Summary

The USG FLEX 700H DHCP server is capable of issuing DHCP option 24 for VOIP equipment, provided the user-defined option is correctly configured on the server and the client requests it as part of its DHCP option 55 list.