From: Derrick Lyndon Pallas <derrick@pallas.us>
To: Roman Mamedov <rm@romanrm.net>
Cc: WireGuard mailing list <wireguard@lists.zx2c4.com>
Subject: Re: Revisiting the weird MTU issue
Date: Wed, 10 Apr 2019 11:20:11 -0700 [thread overview]
Message-ID: <A92609A1-27DC-4DBB-BE8C-BF740A63153B@pallas.us> (raw)
In-Reply-To: <20190410203431.24b55c89@natsu>
MTU discovery isn't supported widely in my experience. My rule has been to set the interface to 1280, which is the minimum allowed.
~Derrick • iPhone
> On Apr 10, 2019, at 8:34 AM, Roman Mamedov <rm@romanrm.net> wrote:
>
> Hello,
>
> I use WireGuard over IPv6 on a PPPoE connection. The Internet interface MTU is
> 1492. By my calculations MTU 1412 on the WG interface should fit.
>
> However, the following occurs on various MTU combinations between the Remote
> (a server in a DC with full 1500 wire MTU) and Local WG interface MTUs:
>
> Fails or not, is whether a within-WG Remote->Local TCP connection (iperf3)
> works fine or hangs up after transferring a few initial bits of data.
>
> Remote Local Result
> ====================
> 1420 1420 Fails (as expected)
>
> 1420 1412 Fails (weird)
>
> 1412 1412 Works (fair enough)
>
> 1420 1408 Works (super weird!!!)
>
> Now I hope I described the situation clearer than the last time posting about
> this, so maybe someone has an idea what could be the culprit?
>
> So far this doesn't cause too much issue, as I'm using on designated p2p links
> for when one of the peers is on this PPPoE, I just use 1412 on both sides. But
> still, surely the above shouldn't happen?
>
> --
> With respect,
> Roman
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> WireGuard@lists.zx2c4.com
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prev parent reply other threads:[~2019-04-10 18:20 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-10 15:34 Roman Mamedov
2019-04-10 18:20 ` Derrick Lyndon Pallas [this message]
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