From nobody Fri Apr 19 15:48:01 2024 X-Original-To: freebsd-stable@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4VLfDf6c84z5HGmW for ; Fri, 19 Apr 2024 15:48:02 +0000 (UTC) (envelope-from des@freebsd.org) Received: from smtp.freebsd.org (smtp.freebsd.org [IPv6:2610:1c1:1:606c::24b:4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4VLfDf64Xtz4WVY; Fri, 19 Apr 2024 15:48:02 +0000 (UTC) (envelope-from des@freebsd.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1713541682; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=WBJapBlmvoiObSCdtEf6GwRmKMb3Hcw6UtNJ+XR4FC0=; b=H8GR0p0aIWvwMZks0vThh7gN/Se3I4AKEHMQLWt1J0K1s8PVu2S3feCoGxX6cBMVIvMren T7va+G2fK2owGURtO0uQ+EoXfE/IAqeGlWh1+dNaNyjkCkhlhEZTxcHIFWMS5S52YDlL7f QUc4QBgzM1u4xiOfc/nLT4mVogMfMja8/wGwUIOrnOnJzY+rAvpCMv4/ndEb1ADUB/bXk5 ASdMoGV5GG7Z5Ismzesc97DEL+nvqnQtxKAzOTO3mhRGjzQiBG+dgHOOmaZhy4X7vinpiR z5pXR7glmOvlt2BP9avBAhUhsN20mn0NhEIyFrGch3ekFs/KDv2EU0TIH2gTXQ== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1713541682; a=rsa-sha256; cv=none; b=aiTp+yZvzYO+v1KlJ+9wr7/XZO4M5+c8g8AmF3+9kjKyaElwFXUEU3aAJipS+rLJojhNcJ UkYsVp0UNEVNwmZ/OInLHMdA6/NCzxBy9XLmSxgK1Rdaw47aGndIpJiMovEg1GKiExtkvs DK2WlMDUGUDOnhMcnoGhnKvhyl+PUnWHBkO8PlMru48ztg3exsh8cATLVJ87Wjiii6EqMw Vao/9zISjs0bVY2USLfXc9QVMXIBUAlln6FVPu1hM+3LpmMWRoZuh8Q4DjgW1t7OLhni3v 6FdRGFvj5P7/DpcdWBtr6+DK2MWyYQtGPjL55KRfxoUBwrONETvwfQANfHBDEQ== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1713541682; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=WBJapBlmvoiObSCdtEf6GwRmKMb3Hcw6UtNJ+XR4FC0=; b=O2lIF0U/cqbBeJSaPGM1OxTAYuTq86QOnz7S0xmNdjTSuAKIQ18wZJ2eccWrO4NBus1UwL WgNWZoyzMAZ6jcT96lkyXs+2Aqn8pnfjhqcx6dWTRd9dBceeLsdCH+P7X+9PVw45TqbOD6 uWNIAZKqKjKbiqUh+Jhao96NwsWR13IaTBbuzhAd7n4Ax/QVlIEZDItppdvk3+6nXivPmV aMFplNlA0EXnyycuFKp8+D8Pbvb2MSQzJZIUwXGGcd/zPI+1foq8fG1B/WiQPU2AeONZLG eMwZUI52tNlNuk4DR8rnkp44yvUc6avlGmu1GY9+NI6Ji0K6EHp1t4ARhwlkkw== Received: from ltc.des.dev (163.23.65.37.rev.sfr.net [37.65.23.163]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) (Authenticated sender: des) by smtp.freebsd.org (Postfix) with ESMTPSA id 4VLfDf4sMdzd7V; Fri, 19 Apr 2024 15:48:02 +0000 (UTC) (envelope-from des@freebsd.org) Received: by ltc.des.dev (Postfix, from userid 1001) id 7249A1E5A9; Fri, 19 Apr 2024 17:48:01 +0200 (CEST) From: =?utf-8?Q?Dag-Erling_Sm=C3=B8rgrav?= To: Gerrit =?utf-8?Q?K=C3=BChn?= Cc: freebsd-stable@freebsd.org Subject: Re: possible regression handling packet fragmentation in 14.0 with tftp/pxe In-Reply-To: <20240419153951.5a23ce5f@arc.aei.uni-hannover.de> ("Gerrit =?utf-8?Q?K=C3=BChn=22's?= message of "Fri, 19 Apr 2024 15:39:51 +0200") References: <20240419153951.5a23ce5f@arc.aei.uni-hannover.de> User-Agent: Gnus/5.13 (Gnus v5.13) Date: Fri, 19 Apr 2024 17:48:01 +0200 Message-ID: <86y1999wwe.fsf@ltc.des.dev> List-Id: Production branch of FreeBSD source code List-Archive: https://lists.freebsd.org/archives/freebsd-stable List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: freebsd-stable@freebsd.org Sender: owner-freebsd-stable@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Gerrit K=C3=BChn writes: > For the following: > 192.168.130.3 is the diskless client trying to boot (Linux) > 192.168.130.253 is the server for nfsroot and tftp (FreeBSD) > 192.168.130.254 is the router and dhcp-server (FreeBSD 13.3/14.0) > [...] > But this suspiciously looked like MTU problems. The VPN only offers an MTU > of 1425 by default, while tftp appears to use 1460. After some > searching and reading I found that the original tftp default was 512 byte > packets, and the client obviously requests larger packets for speed > reasons explicitely with the "blksize 1456" command. Unfortunately, I fou= nd > no way to configure the PXE firmware to use smaller packets. > However, adding the "-o" option to FreeBSD's tftpd could disable all extra > options and forced both the server and the client to user smaller packets. > TFTP and PXE-booting were working fine again after that change. Since you control the routers and endpoints, I would suggest running tcpdump at various points to see what is the tunnel and pf are doing to the UDP packets. They are presumably getting fragmented at some point, and hopefully reassembled somewhere else. Meanwhile you can also set the net.inet.udp.maxdgram sysctl to 1425 on the NFS server, as tftpd will cap the blocksize to that value. DES --=20 Dag-Erling Sm=C3=B8rgrav - des@FreeBSD.org