SIP Servers Generator
Generate Option 120 as an IP address list or domain name list
Generated Output
ISC DHCP (dhcpd) Configuration
Add the generated line to your dhcpd.conf file within the appropriate subnet or host block:
- Open your
/etc/dhcp/dhcpd.conffile - Locate the subnet or host block where you want to apply this option
- Add the generated line from above
- Restart the DHCP service:
systemctl restart isc-dhcp-server
Infoblox Configuration
Use the hex value above to configure DHCP Option 120 in Infoblox:
- Log in to the Infoblox Grid Manager (NIOS)
- Navigate to DHCP → DHCP Options (or Data Management → DHCP → Options)
- Select or create the DHCP option set you want to modify
- Click Add or edit Option 120
- In the option configuration:
- Set Option Type to "Hex" or "Binary"
- Enter the hex value from above in the Value field
- The format should be:
XX:XX:XX:XX(with colons)
- Click Save or Save & Close
- Apply the option set to your network view, network, or DHCP range as needed
Screenshot placeholder: Infoblox DHCP Options configuration screen
Important: The hex value format uses colons (:) as separators. Copy the value exactly as shown above, including the colons.
Windows DHCP Server Configuration
Configure DHCP Option 120 using the hex value above:
- Open DHCP Manager (run
dhcpmgmt.mscor search for "DHCP" in Start menu) - Navigate to your DHCP server → IPv4 → Server Options (for all scopes) or Scope Options (for specific scope)
- Right-click on Server Options or Scope Options and select Configure Options
- In the General tab, scroll down to find Option 120
- Check the box next to Option 120
- In the Data entry section:
- Select Binary or Hex as the data type
- Enter the hex value from above in space-separated format:
XX XX XX XX - Alternatively, you can enter it as a single hex string without spaces
- Click OK to save the configuration
Screenshot placeholder: Windows DHCP Server Options configuration dialog
Alternative Method (PowerShell):
# Convert hex string to byte array and set option
# Replace "HEX_VALUE_HERE" with the raw hex value from above (no spaces, no colons)
$hexValue = "HEX_VALUE_HERE";
$bytes = ($hexValue -split '(..)' | Where-Object { $_ }) | ForEach-Object { [Convert]::ToByte($_, 16) };
Set-DhcpServerv4OptionValue -OptionId 120 -Value $bytes
Note: Replace HEX_VALUE_HERE with the raw hex value from the "Raw Hex" tab above (no spaces, no colons).
Raw Hex Value
This is the raw hexadecimal value without any formatting. Use this for:
- Manual configuration in systems that require raw hex
- Scripts and automation tools
- Testing and validation