Development discussion of WireGuard
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From: "Daniel Gröber" <dxld@darkboxed.org>
To: "Marek Küthe" <m-k-mailling-list@mk16.de>
Cc: wireguard@lists.zx2c4.com, luizluca@gmail.com
Subject: Re: IPv6 and PPPoE with MSSFIX
Date: Wed, 23 Aug 2023 19:14:51 +0200	[thread overview]
Message-ID: <20230823171451.ld2fwslkl6blv6y2@House.clients.dxld.at> (raw)
In-Reply-To: <20230823165840.7bf3b910@parrot>

Hi,

On Wed, Aug 23, 2023 at 04:58:40PM +0200, Marek Küthe wrote:
> PPPoE adds 8 bytes of overhead so that an MTU of 1432 can be used. I
> also have to do this at home with my DSL line for example.
> The MTU should be set on each side (on both peers) for this to work.

Oh, I just realized I used the 1432 MTU in my earlier reply based on
Marek's math but since Luiz's underlay network is IPv6 this is not actually
correct. MTU=1440 is only correct on top of IPv4, for IPv6 the "optimal"
MTU is 1420 so with PPPoE involved that's MTU=1412.

  1500 Ethernet payload
   -40 IPv6 header
    -8 UDP header
   -32 Wg header
    -8 PPPoE
===================
  1412 wg tunnel MTU

--Daniel

  reply	other threads:[~2023-08-23 17:18 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-22 20:39 Luiz Angelo Daros de Luca
2023-08-23 14:58 ` Marek Küthe
2023-08-23 17:14   ` Daniel Gröber [this message]
2023-08-23 19:01     ` Luiz Angelo Daros de Luca
2023-08-23 20:47       ` Hugo Slabbert
2023-08-28 22:22         ` Luiz Angelo Daros de Luca
2023-08-23 17:07 ` Daniel Gröber
2023-08-23 19:55   ` Luiz Angelo Daros de Luca

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