From nobody Wed Jun 21 19:26:52 2023 X-Original-To: freebsd-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 4QmYRF6XxSz4gPJT; Wed, 21 Jun 2023 19:27:05 +0000 (UTC) (envelope-from ccfreebsd@gmail.com) Received: from mail-ot1-f43.google.com (mail-ot1-f43.google.com [209.85.210.43]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1D4" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4QmYRF49hcz47WK; Wed, 21 Jun 2023 19:27:05 +0000 (UTC) (envelope-from ccfreebsd@gmail.com) Authentication-Results: mx1.freebsd.org; none Received: by mail-ot1-f43.google.com with SMTP id 46e09a7af769-6b5d7e60015so539106a34.0; Wed, 21 Jun 2023 12:27:05 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687375624; x=1689967624; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=Uk0Ki0ucy1eUHbru+7yPkbPBeb/1GO1F7ecZAITsmig=; b=Zg+DgEZ48F4t5McNpsgwezPMQyGSHO2S6D04efzR9gomD9Pm3N2siv5BnMnWqKhrhY Kk/2Mf6DvnZ0VS9guJdX6BRifvhZXleUXypR/YhvzrhZMA3GFC62Kgs2COx+gmkCSN/F YJoXBr+t/ZgGRwyiXth4FnvBAagRUHiTdfR8O27e+K6ssb0aQpUzEcjbm+j0RA3jKksB CU7zex2fzRojqLXpUoypVhQwok0jL2lJgllyYuq+WhcA1yTOI9ETNFcoLpB6/FqizvNr 7BSzWfQmeHDnlbI/AwpP44nOHrrYOxdLTb0yWEiipfXjZ1KfVcI2c/3loIAqfaKMAcpW q4bA== X-Gm-Message-State: AC+VfDwpwAc7v+fbNix7kRaRr2UaFFMHCSFvdficDsKfN+/DDW5JyNuI NgIGN04jnbF8B4uOFAzWjbx+K4ZM6Gg= X-Google-Smtp-Source: ACHHUZ6JywvW+3dYn3IkFhMYal3jswcLfyFDrt7mJcN7s4yNliPFmL+HDjniYSXYUVNFizyAqRWAng== X-Received: by 2002:a9d:65c4:0:b0:6af:7f7c:d069 with SMTP id z4-20020a9d65c4000000b006af7f7cd069mr13802302oth.18.1687375623917; Wed, 21 Jun 2023 12:27:03 -0700 (PDT) Received: from mail-oa1-f42.google.com (mail-oa1-f42.google.com. [209.85.160.42]) by smtp.gmail.com with ESMTPSA id v1-20020a0568301bc100b006acd6e5b56bsm2208127ota.15.2023.06.21.12.27.03 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 21 Jun 2023 12:27:03 -0700 (PDT) Received: by mail-oa1-f42.google.com with SMTP id 586e51a60fabf-1a28de15c8aso6325574fac.2; Wed, 21 Jun 2023 12:27:03 -0700 (PDT) X-Received: by 2002:a05:6870:3a03:b0:1a9:8316:9b0a with SMTP id du3-20020a0568703a0300b001a983169b0amr12452712oab.7.1687375623422; Wed, 21 Jun 2023 12:27:03 -0700 (PDT) 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 References: In-Reply-To: From: Cheng Cui Date: Wed, 21 Jun 2023 15:26:52 -0400 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: -current dropping ssh connections To: bob prohaska Cc: freebsd-net@freebsd.org, freebsd-arm@freebsd.org Content-Type: multipart/alternative; boundary="000000000000a3097305fea8c0ad" X-Rspamd-Queue-Id: 4QmYRF49hcz47WK X-Spamd-Bar: ---- X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:15169, ipnet:209.85.128.0/17, country:US] X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-ThisMailContainsUnwantedMimeParts: N --000000000000a3097305fea8c0ad Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable > > There don't seem to be any error messages on the console at all, the > client > session simply reports > client_loop: send disconnect: Broken pipe > Have you tried SSH keepalive? https://stackoverflow.com/questions/25084288/keep-ssh-session-alive Best Regards, Cheng Cui On Wed, Jun 21, 2023 at 1:24=E2=80=AFPM bob prohaska w= rote: > I've got a Pi4 running -current that seems to selectively drop ssh > connections. > > Connections running a shell seem to stay up, but a session running tip to= a > usb-serial adapter (FTDI TTL232R-3V3) seems go away within a few hours. > There don't seem to be any error messages on the console at all, the > client > session simply reports > client_loop: send disconnect: Broken pipe > > Searches through /var/log/sshd_debug.log find many transactions between > the ssh client and the -current target host, but none seem to be error > messages; all are either connection reports or disconnects by user. > > This sort of behavior has been intermittent with aarch64 among both > the Pi4 and a pair of Pi3s for some time, but now only the Pi4 is > dropping connections. > > I've tried searching /var/log/sshd_debug.log for the keywords tip, > ucom, the IP address of the NAT client used to connect and cuaU0. > Are there other things worth looking for? > > Right now I'm using in /etc/rc.conf the line > sshd_flags=3D"-E /var/log/sshd_debug.log" > which is already quite verbose. Is there a better > option that emphasizes errors over normal traffic? > > Thanks for reading, > > bob prohaska > > > > --000000000000a3097305fea8c0ad Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
There don't seem to be any error messages on the console at al= l, the client
session simply reports
client_loop: send disconnect: Broken pipe

Have you tried SSH keepalive?

On Wed, Jun 21, 2023= at 1:24=E2=80=AFPM bob prohaska <= fbsd@www.zefox.net> wrote:
I've got a Pi4 running -current that seems to selecti= vely drop ssh connections.

Connections running a shell seem to stay up, but a session running tip to a=
usb-serial adapter (FTDI TTL232R-3V3) seems go away within a few hours. There don't seem to be any error messages on the console at all, the cl= ient
session simply reports
client_loop: send disconnect: Broken pipe

Searches through /var/log/sshd_debug.log find many transactions between
the ssh client and the -current target host, but none seem to be error
messages; all are either connection reports or disconnects by user.

This sort of behavior has been intermittent with aarch64 among both
the Pi4 and a pair of Pi3s for some time, but now only the Pi4 is
dropping connections.

I've tried searching /var/log/sshd_debug.log for the keywords tip,
ucom, the IP address of the NAT client used to connect and cuaU0.
Are there other things worth looking for?

Right now I'm using in /etc/rc.conf the line
sshd_flags=3D"-E /var/log/sshd_debug.log"
which is already quite verbose. Is there a better
option that emphasizes errors over normal traffic?

Thanks for reading,

bob prohaska



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