From owner-freebsd-bugs@freebsd.org Tue Jan 5 20:46:57 2021 Return-Path: Delivered-To: freebsd-bugs@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 590E24CA160 for ; Tue, 5 Jan 2021 20:46:57 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.nyi.freebsd.org (unknown [127.0.1.3]) by mx1.freebsd.org (Postfix) with ESMTP id 4D9PgP1qs5z3Jjf for ; Tue, 5 Jan 2021 20:46:57 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.nyi.freebsd.org (Postfix) id 3D17A4CA5F8; Tue, 5 Jan 2021 20:46:57 +0000 (UTC) Delivered-To: bugs@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 3CD944CA15F for ; Tue, 5 Jan 2021 20:46:57 +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 "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4D9PgP19z8z3JgG for ; Tue, 5 Jan 2021 20:46:57 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) 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 16C60129DD for ; Tue, 5 Jan 2021 20:46:57 +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 105Kkuqx037539 for ; Tue, 5 Jan 2021 20:46:56 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 105KkuHi037538 for bugs@FreeBSD.org; Tue, 5 Jan 2021 20:46:56 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: bugs@FreeBSD.org Subject: [Bug 252449] telnet(1) regression or incompatibility in recent 12.2-STABLE Date: Tue, 05 Jan 2021 20:46:57 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: bin X-Bugzilla-Version: 12.2-STABLE X-Bugzilla-Keywords: 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: bug_id short_desc product version rep_platform op_sys bug_status bug_severity priority component assigned_to reporter attachments.created Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 05 Jan 2021 20:46:57 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D252449 Bug ID: 252449 Summary: telnet(1) regression or incompatibility in recent 12.2-STABLE Product: Base System Version: 12.2-STABLE Hardware: arm64 OS: Any Status: New Severity: Affects Only Me Priority: --- Component: bin Assignee: bugs@FreeBSD.org Reporter: zarychtam@plan-b.pwste.edu.pl Created attachment 221307 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=3D221307&action= =3Dedit Traffic dumps I have recently upgraded a few systems running 12.2-STABLE and after upgrad= ing one by one I am losing the ability to connect with some Alcatel-Lucent swit= ches (Omniswitch 63xx and 64xx models). Connection with the host seems to be established, but I am not able to get the login prompt: telnet 172.x.x.x Trying 172.x.x.x... Connected to 172.x.x.x. Escape character is '^]'. ^] This state last forever and the session can be only terminated. Telneting to other devices, from other vendors or even some different ALU switches, still goes fine. Since I was upgrading systems one by one and losing connectivity, I took so= me tcpdumps to document this oddity. Perhaps the culprit is TCP stack or its settings, which are the same on all machines: net.inet.tcp.ecn.enable=3D1 net.inet.tcp.nolocaltimewait=3D1 net.inet.tcp.mssdflt=3D1448 net.inet.tcp.syncache.rexmtlimit=3D1=20 net.inet.tcp.drop_synfin=3D1 net.inet.tcp.rfc6675_pipe=3D1 net.inet.tcp.abc_l_var=3D44 net.inet.tcp.functions_default=3Drack net.inet.tcp.cc.algorithm=3Dhtcp net.inet.tcp.cc.htcp.rtt_scaling=3D1 net.inet.tcp.cc.htcp.adaptive_backoff=3D1 net.inet.tcp.fastopen.server_enable=3D1 When the system is booted from kernel.old telnet from new userland and above TCP stack settings is able to connect again. --=20 You are receiving this mail because: You are the assignee for the bug.=