/** \brief IP neighbor add / del request
@param client_index - opaque cookie to identify the sender
@param context - sender context, to match reply w/ request
/** \brief IP neighbor add / del request
@param client_index - opaque cookie to identify the sender
@param context - sender context, to match reply w/ request
@param sw_if_index - interface used to reach neighbor
@param is_add - 1 to add neighbor, 0 to delete
@param is_ipv6 - 1 for IPv6 neighbor, 0 for IPv4
@param sw_if_index - interface used to reach neighbor
@param is_add - 1 to add neighbor, 0 to delete
@param is_ipv6 - 1 for IPv6 neighbor, 0 for IPv4