From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: rm@romanrm.net Received: from krantz.zx2c4.com (localhost [127.0.0.1]) by krantz.zx2c4.com (ZX2C4 Mail Server) with ESMTP id ae5cb2a6 for ; Sun, 12 Aug 2018 18:54:35 +0000 (UTC) Received: from rin.romanrm.net (rin.romanrm.net [IPv6:2001:41d0:1:8b3b::1]) by krantz.zx2c4.com (ZX2C4 Mail Server) with ESMTP id 080d13dc for ; Sun, 12 Aug 2018 18:54:35 +0000 (UTC) Date: Mon, 13 Aug 2018 00:06:11 +0500 From: Roman Mamedov To: StarBrilliant Subject: Re: Fragmentation on UDP layer possible? Message-ID: <20180813000611.3296fa66@natsu> In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Cc: wireguard@lists.zx2c4.com List-Id: Development discussion of WireGuard List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, 13 Aug 2018 02:53:44 +1000 StarBrilliant wrote: > I know Wireguard can already do IP layer fragmentation. (Just set > tunnel MTU >= 1441 then fragmentation will be turned on) Is that really expected to work? I tried setting MTU 9000 on both ends of a WG tunnel, but large packets still do not seem to come through properly. Did you try using it like that in any kind of environment (aside from that one restrictive network)? In theory using MTU 9000 or such would help lower the huge overhead percentage of running IP over VXLAN over IP over WG over IP. I was looking into that the other day, but my idea was to fragment VXLAN packets across multiple WG ones, which turned out to be impossible (VXLAN RFC forbids fragmentation). -- With respect, Roman