On Thu, 21 Jan 2021 19:07:18 +0500 Roman Mamedov <r...@romanrm.net> wrote:
> On Sun, 17 Jan 2021 11:36:42 +0100 > Harald Dunkel <ha...@afaics.de> wrote: > > > Hi folks, > > > > I am using PPPoE to connect to my IP provider. To use wireguard on Linux I > > have to reduce the MTU in wg0.conf to 1400. Using the default 1420 a ssh > > connection tunneled through wireguard gets stuck (reproducible). An echo > > of a very long line (e.g. 4096 chars) is sufficient. > > > > The weird part is, MTU 1420 works fine for wireguard on MacOS. How comes > > that Wireguard appears to be more stable on MacOS than on Linux? > > WireGuard works just fine for me on Linux using MTU 1432 if over IPv4, and > 1412 if over IPv6. The underlying PPPoE device MTU is 1492 in my case. Check > which PPPoE MTU you use in Linux vs in MacOS. > Oh, and I just remembered -- you're better off setting the same MTU on the entire WG network, i.e. substract those 8 bytes of PPPoE interface on the remote host's WG interface as well. Else the local interface MTU will need a weird and so far unexplained further 4-byte reduction for things to work: https://lists.zx2c4.com/pipermail/wireguard/2019-April/004078.html -- With respect, Roman