--- sendip.c.orig Fri Dec 26 15:31:29 2014 +++ sendip.c Tue Nov 22 03:17:46 2016 @@ -111,7 +111,11 @@ void send_ip (char* src, char *dst, char *data, unsign (struct sockaddr*)&remote, sizeof(remote)); if (result == -1 && errno != EINTR && !opt_rand_dest && !opt_rand_source) { + int save_errno = errno; perror("[send_ip] sendto"); + if (save_errno == EHOSTUNREACH) + printf("[send_ip] " + "Note that PF might be blocking your packets.\n"); if (close(sockraw) == -1) perror("[ipsender] close(sockraw)"); if (close_pcap() == -1)