marshal_u32
marshal_u32(b, 0);
marshal_u32(b, n);
marshal_u32(b, p->max_refresh_time);
marshal_u32(b, p->min_refresh_time);
marshal_u32(b, p->max_retry_time);
marshal_u32(b, p->min_retry_time);
marshal_u32(b, p->min_expire_time);
marshal_u32(b, p->ixfr_number);
marshal_u32(b, p->verifier_timeout);