Int 60 Fn 06 - Ftp Packet Driver - Basic Func - Get Address [N]
AH = 06h
BX = handle (optional for v1.10+)
ES:DI -> buffer
CX = length
Return: CF set on error
DH = error code (see #2976)
CF clear if successful
CX = length
Note: copies the local net address associated with the handle into the buffer