Multicast is pinned to the beacon in a conventional wifi setup, usually on a 100ms interval.
Sorry I have no further insights to offer at the moment (5AM here). On Wed, May 4, 2022 at 5:16 AM Juliusz Chroboczek <[email protected]> wrote: > > > > 1. Are you running with the "unicast" option set in your config file? > > > > Aaah turns out I was, because I had it set in `default` for my wireguard > > links. > > > > Adding `interface enpxx unicast false` magically fixes this. According to > > the docs this skips sending a duplicate hello to neighbours which would > > explain why it works. > > Not quite. Babel has three kinds of TLVs: > > - Discovery Hellos, which are always sent over multicast; > - requests, which are always sent over unicast; > - the bulk of the protocol, which may be sent either over multicast or > unicast. > > The unicast option controls whether the bulk of the protocol is sent over > multicast (unicast off) or sent to each peer over unicast (unicast on). > In your case, Babel was sending > > Hello multicast > IHU unicast > > The Hello and the IHU were getting reordered, so the Hello was getting > dropped due to an incorrect packet counter value. With "unicast false", > Babel is sending a single aggregated Hello+IHU over multicast, so no > reordering can happen. > > We still need to understand why you're getting systematic packet > reordering. If it's something that cannot be avoided, then we will need > to update the HMAC implementation (and spec!) to maintain a replay window, > in the style of > > https://datatracker.ietf.org/doc/html/rfc4303#section-3.4.3 > > > Where are you getting the 200ms number from exactly? > > Here: > > 10:24:31.056310 IP6 fe80::1.6696 > fe80::c23c:59ff:fe4a:ce46.6696 > Router Id 02:0d:b9:ff:fe:4e:90:54 > Update/prefix... > PC value 57567 index len 8 > > 10:24:31.257774 IP6 fe80::1.6696 > ff02::1:6.6696 > Hello seqno 36696 interval 4.00s > PC value 57566 index len 87 > > It's suspiciously close to 200ms (201.5ms exactly). Toke, you're the > world specialist of the Linux WiFi stack -- do you see a hardwired 200ms > delay somewhere? > > -- Juliusz > > _______________________________________________ > Babel-users mailing list > [email protected] > https://alioth-lists.debian.net/cgi-bin/mailman/listinfo/babel-users -- FQ World Domination pending: https://blog.cerowrt.org/post/state_of_fq_codel/ Dave Täht CEO, TekLibre, LLC _______________________________________________ Babel-users mailing list [email protected] https://alioth-lists.debian.net/cgi-bin/mailman/listinfo/babel-users
