On Thu, 2021-03-11 at 15:50 +0100, Ondrej Zajicek wrote: > On Thu, Mar 11, 2021 at 12:35:40PM +0000, Joakim Tjernlund wrote: > > We have a ring of routers(5 of them) running unnumbered pppoe links between > > them. Adding OSPF authentication (auth trailer) works OK. > > However, removing OSPFv3 on ONE interface causes big problem in some cases, > > we loose auth in the whole ring > > and routing is then kaputt for all routers. > > > > We have noted that some PDUs(like LS update) are sent without auth trailer > > so the receiving nodes > > complains with "ospfv3_2: Authentication failed for nbr 0.0.139.1 on > > p1-1-3-1-4 - missing authentication trailer (0)" > > > > OSPFv3 Hello is OK though, it still has its auth trailer. > > Hmm, that is strange. There is difference between Hello and LSUpd in > OSPFv3 Auth receiver code, but not in sending code. That is essentially: > > if (ifa->autype != OSPF_AUTH_CRYPT) > return; > > ... attach auth trailer ... > > > > Any ideas? > > LSUpd packets do not contain explicit flag whether they use OSPFv3 auth > trailer. Such information is stored in neighbor structure based on > received DBDes packet. So 'missing authentication trailer' for LSUpd > really means that such neighbor structure says 'no auth'. But that > should not happen as that DBDes packet would be rejected. > > One idea is that DBDes packets intended for one iface (non-authenticated) > were sent to a different iface (authenticated) and they poisoned neighbor > structure with 'no auth' info. > > You say 'loose auth in the whole ring', i can imagine that it will break > adjacent links, but it will really break even non-adjacent links? >
Yes, it takes some time(about 30 min) though before the whole ring is gone. All nodes are seeing "missing authentication trailer" msg.