diff --git a/src/server.c b/src/server.c
index 0b43bf0..c04f829 100644
--- a/src/server.c
+++ b/src/server.c
@@ -1095,8 +1095,10 @@ static int handle_sabm(patty_ax25_server *server,
         goto error_sock_delete_by_addr;
     }
 
-    if (reply_ua(iface, frame, PATTY_AX25_FRAME_FINAL) < 0) {
-        goto error_reply_ua;
+    if (frame->pf) {
+        if (reply_ua(iface, frame, PATTY_AX25_FRAME_FINAL) < 0) {
+            goto error_reply_ua;
+        }
     }
 
     memset(&response, '\0', sizeof(response));
@@ -1231,7 +1233,7 @@ static int handle_i(patty_ax25_server *server,
                     patty_ax25_sock *sock,
                     patty_ax25_frame *frame) {
     if (sock == NULL || sock->status != PATTY_AX25_SOCK_ESTABLISHED) {
-        return reply_dm(iface, frame, PATTY_AX25_FRAME_FINAL);
+        return frame->pf? reply_dm(iface, frame, PATTY_AX25_FRAME_FINAL): 0;
     }
 
     /*
@@ -1243,7 +1245,18 @@ static int handle_i(patty_ax25_server *server,
         return patty_ax25_sock_send_rej(sock);
     }
 
-    return write(sock->fd, frame->info, frame->infolen);
+    if (write(sock->fd, frame->info, frame->infolen) < 0) {
+        goto error_write;
+    }
+
+    if (frame->pf) {
+        return patty_ax25_sock_send_rr(sock);
+    }
+
+    return 0;
+
+error_write:
+    return -1;
 }
 
 static int handle_disc(patty_ax25_server *server,
@@ -1261,7 +1274,11 @@ static int handle_disc(patty_ax25_server *server,
         goto error_sock_delete;
     }
 
-    return reply_dm(iface, frame, PATTY_AX25_FRAME_FINAL);
+    if (frame->pf) {
+        return reply_dm(iface, frame, PATTY_AX25_FRAME_FINAL);
+    }
+
+    return 0;
 
 error_sock_delete:
     return -1;