--- openssh-2.3.0p1-orig/clientloop.c	Sat Feb 17 22:48:00 2001
+++ openssh-2.3.0p1/clientloop.c	Sat Feb 17 22:45:52 2001
@@ -364,6 +364,9 @@
 void
 client_wait_until_can_do_something(fd_set * readset, fd_set * writeset)
 {
+        struct timeval tv = {0};
+        tv.tv_sec = 180;    /* Send a noop message every three minutes as a keepalive. */
+    
 	/* Initialize select masks. */
 	FD_ZERO(readset);
 	FD_ZERO(writeset);
@@ -411,7 +414,8 @@
 	 * SSH_MSG_IGNORE packet when the timeout expires.
 	 */
 
-	if (select(max_fd + 1, readset, writeset, NULL, NULL) < 0) {
+	switch (select(max_fd + 1, readset, writeset, NULL, &tv)) {
+            case -1: {
 		char buf[100];
 		/* Some systems fail to clear these automatically. */
 		FD_ZERO(readset);
@@ -423,7 +427,21 @@
 		buffer_append(&stderr_buffer, buf, strlen(buf));
 		stderr_bytes += strlen(buf);
 		quit_pending = 1;
-	}
+                
+            }
+            break;
+            
+            case 0:
+                /* Send a keepalive packet (not SSH_MSG_IGNORE as this crashes
+                 * some servers...).
+                 */
+                packet_start(SSH_MSG_NONE);
+                packet_send();
+                break;
+
+            default:
+                break;
+        }
 }
 
 void