diff -Naur stunnel-4.18/src/client.c stunnel-4.18-extra-logging/src/client.c
--- stunnel-4.18/src/client.c	2006-08-23 11:35:32.000000000 +0200
+++ stunnel-4.18-extra-logging/src/client.c	2006-10-05 10:20:03.672581056 +0200
@@ -928,6 +928,18 @@
 }
 #endif
 
+void connect_log_source(int s) {
+    struct sockaddr_in cliaddr;
+    socklen_t cliaddrlen = sizeof(struct sockaddr_in);
+
+    memset(&cliaddr, 0, sizeof(cliaddr));
+    if (getsockname(s, (struct sockaddr *) &cliaddr, &cliaddrlen)) {
+        sockerror("getsockname() error");
+    } else {
+        s_log(LOG_NOTICE,"connected to backend from %s:%d", inet_ntoa(cliaddr.sin_addr), ntohs(cliaddr.sin_port));
+    }
+}
+
 static int connect_remote(CLI *c) { /* connect to remote host */
     SOCKADDR_UNION bind_addr, addr;
     SOCKADDR_LIST resolved_list, *address_list;
@@ -975,6 +987,7 @@
         if(!connect(c->fd, &addr.sa, addr_len(addr))) {
             fd=c->fd;
             c->fd=-1;
+            connect_log_source(fd);
             return fd; /* no error -> success (should not be possible) */
         }
         error=get_last_socket_error();
@@ -989,6 +1002,7 @@
             longjmp(c->err, 1);
         fd=c->fd;
         c->fd=-1;
+        connect_log_source(fd);
         return fd; /* success! */
     }
     longjmp(c->err, 1);