> When ypserv doesn dns lookups on behalf of its clients with the -b hack, > it is using libresolv, so this case also involves Sun's mucking. Ok, I've always been speaking about libc(shared or not) here, and at least two of you are now speaking about libresolv.a. Was I confused, or did someone change the subject? Yes, the gethostbyaddr() call in libresolv has the reverse lookup. No, its done in a different place inside ypserv. ypserv has its own, special version of the resolver library, and does: if (!found_addr) { /* weve been spoofed */ syslog(LOG_CRIT, "nres_gethostbyaddr: %s != %s", temp->name, inet_ntoa(temp->theaddr)); theans = NULL; temp->h_errno = HOST_NOT_FOUND; } in nres_dorecv(). Jim