Date: Tue, 30 Jul 2024 14:53:28 -0700 From: Alex Arslan <ararslan@comcast.net> To: Bakul Shah <bakul@iitbombay.org> Cc: FreeBSD Hackers <freebsd-hackers@freebsd.org> Subject: Re: Diagnosing virtual machine network issues Message-ID: <A9069EB9-2CFE-4A9A-98AD-2C8085873163@comcast.net> In-Reply-To: <2B0A1E6F-7B89-4F7C-9ECE-ABA94E476D5A@iitbombay.org> References: <FA265FAA-216D-4DCC-92C0-50017C17F7DE@comcast.net> <4a5a177a-5356-453c-8a09-f1d63d5d2e16@sentex.net> <4AB1C33B-DD93-4484-B63A-9FF8FE612B15@comcast.net> <E72DA395-3C66-4520-B58B-31C19E7462A3@comcast.net> <799c7a15-52b8-4b44-bcbd-5ab6a3ef97a6@gmail.com> <0747ED5F-2ED6-461C-9C0B-CFD0EE480D82@comcast.net> <2B0A1E6F-7B89-4F7C-9ECE-ABA94E476D5A@iitbombay.org>
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--Apple-Mail=_ABE8E1E7-5527-4C1F-88D6-08A485B4B25D Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 > On Jul 30, 2024, at 2:22=E2=80=AFPM, Bakul Shah <bakul@iitbombay.org> = wrote: >=20 >> On Jul 30, 2024, at 2:11=E2=80=AFPM, Alex Arslan = <ararslan@comcast.net> wrote: >>=20 >>> Can you provide more context? I'm not seeing earlier messages = anywhere in my email folders. Is this a Qemu issue? >>=20 >> The original message is from just over a month ago, archived here: >> = https://lists.freebsd.org/archives/freebsd-hackers/2024-June/003378.html >> Basically, we have FreeBSD 13.2 VMs running under KVM on a Linux = machine. >> Some code is using libcurl to make a request to an invalid domain and = is >> testing that the error is a resolution failure. This test passes on = all >> platforms except specifically in these FreeBSD VMs; I can't reproduce >> locally on FreeBSD. That made me think that there's an issue with how = the >> VM was set up, prompting the original message and discussion. Then = what >> I recently found was that we set a 30-second timeout for the libcurl >> request, which FreeBSD hits in the VM, as it evidently spends a full >> 30 seconds attempting to resolve the host, while e.g. Linux reports a >> resolution failure immediately. >=20 > What does /etc/resolv.conf look like on the FreeBSD VM? Just a comment and a name server line: $ cat /etc/resolv.conf # Generated by resolvconf nameserver 192.168.122.1= --Apple-Mail=_ABE8E1E7-5527-4C1F-88D6-08A485B4B25D Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8 <html><head><meta http-equiv=3D"content-type" content=3D"text/html; = charset=3Dutf-8"></head><body style=3D"overflow-wrap: break-word; = -webkit-nbsp-mode: space; line-break: = after-white-space;"><br><div><blockquote type=3D"cite"><div>On Jul 30, = 2024, at 2:22=E2=80=AFPM, Bakul Shah <bakul@iitbombay.org> = wrote:</div><div><br style=3D"caret-color: rgb(0, 0, 0); font-family: = Helvetica; font-size: 12px; font-style: normal; font-variant-caps: = normal; font-weight: 400; letter-spacing: normal; text-align: start; = text-indent: 0px; text-transform: none; white-space: normal; = word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: = none;"><blockquote type=3D"cite" style=3D"font-family: Helvetica; = font-size: 12px; font-style: normal; font-variant-caps: normal; = font-weight: 400; letter-spacing: normal; orphans: auto; text-align: = start; text-indent: 0px; text-transform: none; white-space: normal; = widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; = text-decoration: none;">On Jul 30, 2024, at 2:11=E2=80=AFPM, Alex Arslan = <ararslan@comcast.net> wrote:<br><br><blockquote type=3D"cite">Can = you provide more context? I'm not seeing earlier messages anywhere = in my email folders. Is this a Qemu issue?<br></blockquote><br>The = original message is from just over a month ago, archived = here:<br>https://lists.freebsd.org/archives/freebsd-hackers/2024-June/0033= 78.html<br>Basically, we have FreeBSD 13.2 VMs running under KVM on a = Linux machine.<br>Some code is using libcurl to make a request to an = invalid domain and is<br>testing that the error is a resolution failure. = This test passes on all<br>platforms except specifically in these = FreeBSD VMs; I can't reproduce<br>locally on FreeBSD. That made me think = that there's an issue with how the<br>VM was set up, prompting the = original message and discussion. Then what<br>I recently found was that = we set a 30-second timeout for the libcurl<br>request, which FreeBSD = hits in the VM, as it evidently spends a full<br>30 seconds attempting = to resolve the host, while e.g. Linux reports a<br>resolution failure = immediately.<br></blockquote><br style=3D"caret-color: rgb(0, 0, 0); = font-family: Helvetica; font-size: 12px; font-style: normal; = font-variant-caps: normal; font-weight: 400; letter-spacing: normal; = text-align: start; text-indent: 0px; text-transform: none; white-space: = normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; = text-decoration: none;"><span style=3D"caret-color: rgb(0, 0, 0); = font-family: Helvetica; font-size: 12px; font-style: normal; = font-variant-caps: normal; font-weight: 400; letter-spacing: normal; = text-align: start; text-indent: 0px; text-transform: none; white-space: = normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; = text-decoration: none; float: none; display: inline !important;">What = does /etc/resolv.conf look like on the FreeBSD = VM?</span></div></blockquote></div><div><br></div>Just a comment and a = name server line:<div><br><div><div>$ cat /etc/resolv.conf</div><div># = Generated by resolvconf</div><div>nameserver = 192.168.122.1</div></div></div></body></html>= --Apple-Mail=_ABE8E1E7-5527-4C1F-88D6-08A485B4B25D--
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