From nobody Sat Apr 15 12:39:44 2023 X-Original-To: net@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 4PzCZ93kJ9z45G09 for ; Sat, 15 Apr 2023 12:39:45 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (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 "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4PzCZ924h7z3DGl for ; Sat, 15 Apr 2023 12:39:45 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1681562385; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=S80TOc8/sFspa7qyUz/vttt1Uj/ONsjCAf80wF3tWF8=; b=As2ggIURGg/hVypP9suNZtjTAXA4SeeOvXFxkeLXFXUS8BDyhH92f/t3kmqMyLa9hiJ+Xv Og3IdejSIC7ZASzI84xJ67sviLGDBTTrt/pKzqAWMT3CKGWrBtSpIkutvnZMhwaMLnTk5w GYqneO1YIIQ7+CRKjjhWgP7BNcvoixs1iVfZV6kr46hMNyMbefEnRRNU0zil5zcSgVszwh yh3Ifhy85Ax/5FZlixZiE/LfUkyhP2A+pMpH+KgDjFQMT9tcup28r0ETMPVJzxIXKMtchR f3BF6jTCjEyp13P+vNtYaRVpIMggUE+4/N3PIHVTZmoKf72Bl3oMj7QxXdCKng== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1681562385; a=rsa-sha256; cv=none; b=P0lfS7YUYBf4anqg2IR59mNCUQdVBgfUaFwYyqT0VDR1evcOlqNkTgUrxaB4uI2rW9NBm5 OeVIWawjyFngTGa2pp35jhFYs8i19uFlg/8N+vDvnLuvYnIGsa+qYbWLzupdtIRa4gL1k7 rgW9fdhR4aJgL34wd+FSbaQWt4kWvWgoV/ob9vtbZ/Nhs2XoNUc80/S/OHNlkf0LoFrM0+ on73gBgs8aS3tX/QKGcpaDgWfW38b3Wwv60puyvKFQm0u5Jgu2RTa6ES1W0KbZ7CLNPA2l DIF3jGpuxfr5V4uNPJJb1YFrgxueMg9Kddpzp45PNOitkX+oYfGne7c0OPXy3w== Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (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) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4PzCZ912QWz15fj for ; Sat, 15 Apr 2023 12:39:45 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id 33FCdjJn048018 for ; Sat, 15 Apr 2023 12:39:45 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 33FCdjb2048017 for net@FreeBSD.org; Sat, 15 Apr 2023 12:39:45 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: net@FreeBSD.org Subject: [Bug 260260] igb(4) I35{0,4} parrent <--> vlan jumbo frame mtu mismatch Date: Sat, 15 Apr 2023 12:39:44 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 13.0-STABLE X-Bugzilla-Keywords: regression X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: zarychtam@plan-b.pwste.edu.pl X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated List-Id: Networking and TCP/IP with FreeBSD List-Archive: https://lists.freebsd.org/archives/freebsd-net List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-net@freebsd.org MIME-Version: 1.0 X-ThisMailContainsUnwantedMimeParts: N https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D260260 --- Comment #8 from Marek Zarychta --- The bug seems to be not related to lagg(4). Moreover, I found out that it c= an be also worked around by only temporarily oversizing MTU by one byte.=20 So to reproduce the problem issue this sequence of commands: ifconfig igb3 mtu 9000 ifconfig vlan1500 create vlandev igb3 vlan 1500 ifconfig vlan1500 192.168.40.5/24 Now MTU for both igb3 and vlan1500 is set to 9000 but vlan1500 can only send large TCP segments. Receiving is broken. But the real mystery is that after the sequence:=20 ifconfig igb3 mtu 9001 ifconfig igb3 mtu 9000 ifconfig vlan1500 create vlandev igb3 vlan 1500 ifconfig vlan1500 192.168.40.5/24 Receiving large TCP segments for vlan1500 is working fine (MTU for both igb3 and vlan1500 is still set to the same value of 9000).=20 I tried to investigate how can it be possible that when sibling setups are compared one of them is able to work without oversizing MTU of the parent b= ut another one does not. Neither TSO nor LRO seems to be involved. Here's how the segment looks at receiving side after applying a temporary M= TU oversizing fix from the above: 14:27:36.269125 ac:1f:6b:02:aa:bb > ac:1f:6b:02:aa:cc, ethertype IPv4 (0x0800), length 9014: (tos 0x2,ECT(0), ttl 64, id 0, offset 0, flags [DF], proto TCP (6), length 9000) 192.168.40.3.25218 > 192.168.40.5.5201: Flags [.], cksum 0x1a28 (correc= t), seq 835179525:835188473, ack 1, win 70, options [nop,nop,TS val 2309578650 = ecr 1068877401], length 8948 --=20 You are receiving this mail because: You are on the CC list for the bug.=