firstname.lastname@example.org writes: > From: Leon Schuermann <email@example.com> > > This patch series is an attempt to integrate a per-peer MTU setting > into WireGuard. With matching changes to the wireguard-tools, > individual MTU values can be set and retrieved for each registered > peer. > > While Linux supports setting an MTU metric for specific FIB route > entries [which I've only found out after implementing this :)], and > thus allows to lower the MTU for individual peers, this appears to > disable regular path MTU discovery (PMTUD) entirely on the > route. While regular PMTUD does not work over the tunnel link, it > should still be usable on the rest of the route.
I'm not sure I understand the use case? Either PMTUD works through the tunnel and you can just let that do its job, or it doesn't and you have to do out-of-band discovery anyway in which case you can just use the FIB route MTU? Or what do you mean by "usable on the rest of the route"? > Furthermore, with the goal of eventually introducing an in-band > per-peer PMTUD mechanism, keeping an internal per-peer MTU value does > not require modifying the FIB and thus potentially interfere with > userspace. What "in-band per-peer PMTUD mechanism"? And why does it need this? -Toke