@param client_index - opaque cookie to identify the sender
@param pid - client pid registered to receive notification
@param is_ipv6 - if non-zero the address is ipv6, else ipv4
@param client_index - opaque cookie to identify the sender
@param pid - client pid registered to receive notification
@param is_ipv6 - if non-zero the address is ipv6, else ipv4