s = format (s, "src_sw_if_index %u ", ntohl (mp->sw_if_index_from));
s = format (s, "dst_sw_if_index %u ", ntohl (mp->sw_if_index_to));
s = format (s, "src_sw_if_index %u ", ntohl (mp->sw_if_index_from));
s = format (s, "dst_sw_if_index %u ", ntohl (mp->sw_if_index_to));