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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 01FC1C433E0 for ; Thu, 21 Jan 2021 14:07:25 +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 63EB8239A4 for ; Thu, 21 Jan 2021 14:07:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 63EB8239A4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=romanrm.net 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 2ae93473; Thu, 21 Jan 2021 14:07:21 +0000 (UTC) Received: from rin.romanrm.net (rin.romanrm.net [51.158.148.128]) by lists.zx2c4.com (ZX2C4 Mail Server) with ESMTPS id 32b5e7b4 (TLSv1.3:AEAD-AES256-GCM-SHA384:256:NO) for ; Thu, 21 Jan 2021 14:07:19 +0000 (UTC) Received: from natsu (unknown [IPv6:fd39::e99e:8f1b:cfc9:ccb8]) by rin.romanrm.net (Postfix) with SMTP id 888B2385; Thu, 21 Jan 2021 14:07:18 +0000 (UTC) Date: Thu, 21 Jan 2021 19:07:18 +0500 From: Roman Mamedov To: Harald Dunkel Cc: wireguard@lists.zx2c4.com Subject: Re: mtu on Linux vs MacOS Message-ID: <20210121190718.13465dea@natsu> In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit 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" On Sun, 17 Jan 2021 11:36:42 +0100 Harald Dunkel wrote: > Hi folks, > > I am using PPPoE to connect to my IP provider. To use wireguard on Linux I > have to reduce the MTU in wg0.conf to 1400. Using the default 1420 a ssh > connection tunneled through wireguard gets stuck (reproducible). An echo > of a very long line (e.g. 4096 chars) is sufficient. > > The weird part is, MTU 1420 works fine for wireguard on MacOS. How comes > that Wireguard appears to be more stable on MacOS than on Linux? WireGuard works just fine for me on Linux using MTU 1432 if over IPv4, and 1412 if over IPv6. The underlying PPPoE device MTU is 1492 in my case. Check which PPPoE MTU you use in Linux vs in MacOS. -- With respect, Roman