def generate_option_61(client_id):
# Option 61 format: <type><length><value>
# Type: 1 byte, Length: 1 byte, Value: variable length
option_type = b'\x3d' # Option 61 type (Client Identifier)
option_length = bytes([len(client_id) + 1]) # Length of client ID + 1 for type
option_value = b'\x00' + client_id.encode() # Type (Ethernet) + Client ID
return option_type + option_length + option_value
# Prompt user to input client ID
client_id = input("Enter Client ID (ASCII string, max 255 bytes): ")
# Sanity check: Ensure client ID length is less than 255 bytes
if len(client_id.encode()) > 254:
print("Error: Client ID length exceeds 255 bytes.")
exit()
# Example usage:
option_61 = generate_option_61(client_id)
print("Option 61 DHCP Client ID:", option_61.hex())
