From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 459B4C433B4 for ; Wed, 14 Apr 2021 21:51:25 +0000 (UTC) Received: from lists.zx2c4.com (lists.zx2c4.com [165.227.139.114]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0F69A60FF0 for ; Wed, 14 Apr 2021 21:51:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0F69A60FF0 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=stha.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=wireguard-bounces@lists.zx2c4.com Received: by lists.zx2c4.com (ZX2C4 Mail Server) with ESMTP id 22c3342b; Wed, 14 Apr 2021 21:51:22 +0000 (UTC) Received: from deponia.stha.de (deponia.stha.de [2001:8d8:1801:133::1]) by lists.zx2c4.com (ZX2C4 Mail Server) with ESMTPS id f242c114 (TLSv1.3:AEAD-AES256-GCM-SHA384:256:NO) for ; Wed, 14 Apr 2021 21:51:20 +0000 (UTC) Received: from mail.stha.de (mail.stha.de [IPv6:2a03:4000:24:7d0:100::15]) by deponia.stha.de (Postfix) with ESMTPS id 346E110FD07 for ; Wed, 14 Apr 2021 21:51:19 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: stefan) by mail.stha.de (Postfix) with ESMTPSA id E36F1184B91 for ; Wed, 14 Apr 2021 21:50:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=stha.de; s=20200509; t=1618437049; bh=EhySSzkzFES501HWM4oH70JebTareYd2Q579BKQEHmo=; h=Date:From:To:Subject:References:In-Reply-To:From; b=mro6pCT5mJr/LB00lsJt5yTfZzCkA83RVpHwDOav83D6zoDW2hvl/mmw9wY+2rq0R 74QtF6ZD4T/GuYWYeswhEnzZEEGSC/FscnkZZyH+AVRrKRtRU9HhHDEYBxhBQ50t7T rl9hPPwcEnskmne5y2a50A6FusmnM7K+pqr+w7Qu0Zm0HDU3joHmz24/ute1y+9HXC w05+8bfT5QHUlwtIXadNfDhsERc/QhjsV2tJAjaPwib0cd0o7CZRw/Fx2bZ7U2ouZS vXkf16uRakvRIaQ51MEa/N5VdcvG/4nvN6k5yuEyxzZy5L+2no2NrF4zSgQTJM/alR V/3B5ffVG6o2g== Date: Wed, 14 Apr 2021 23:50:45 +0200 From: Stefan Haller To: WireGuard mailing list Subject: Re: FreeBSD if_wg POINTTOPOINT and MULTICAST behaviour Message-ID: <87371254-15f1-494b-8740-38071d7f7d68@stha.de> References: <9afe6dc9-5c53-4c25-b09f-5b4cf6ff8046@stha.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-BeenThere: wireguard@lists.zx2c4.com X-Mailman-Version: 2.1.30rc1 Precedence: list List-Id: Development discussion of WireGuard List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: wireguard-bounces@lists.zx2c4.com Sender: "WireGuard" Hi Jason, Thanks for your clarification. I understand that setting this flag would be a false promise to userspace, because generally Wireguard is point-to-multipoint and doesn't copy messages to multiple peers (which is not exactly necessary in my case, where only a single peer is configured on both sides). I just wanted to ensure that the introduced change was intentional before looking into other directions, hence my question. On Wed, Apr 14, 2021 at 02:24:20PM -0600, Jason A. Donenfeld wrote: > Does bird completely ignore interfaces without it? Is there no setting > to change that? At least a brief look at the code suggests this: [1] The Babel protocol seems to rely on well-known *link-local* IPv6 multicast addresses. I did not find anything related to unicast "hello" messages in the RFC or in the implementations. (OSPF is similar, but as far as I remember unicast hellos are explicitly allowed.) One odd thing I noticed: On Linux (5.11.13-arch1-1, so quite recent), the interface does not list the MULTICAST flag and the interface is still used by bird: # ip l show dev wg1 4: wg1: mtu 1400 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000 I will have a closer look why it doesn't work on FreeBSD but the same thing works on Linux. I am probably missing something important. Kind regards, Stefan [1]: https://gitlab.nic.cz/labs/bird/-/blob/9c41e1ca3e93d4498eaa085139caf1545e08c1d8/proto/babel/babel.c#L1662