On 11/23/20 5:23 PM, Stephen Suryaputra wrote: > Hi, > > I'm running into a problem with lladdr pinging all-host mcast all nodes > addr. The ping intially works but after cycling the interface that > receives the ping, the echo request packet causes a neigh solicitation > being sent on a different interface. > > To repro, I included the attached namespace scripts. This is the > topology and an output of my test. > > # +-------+ +----------+ +-------+ > # | h0 | | r0 | | h1 | > # | v00+-----+v00 v01+---+v10 | > # | | | | | | > # +-------+ +----------+ +-------+ >
after setup, ip netns exec h0 ping -c 1 ff02::1%h0_v00 works, but ip netns exec h1 ping -c 1 ff02::1%h1_v10 does not. No surprise then that cycling v00 in r0 causes the reverse. The problem is the route order changes: root@ubuntu-c-2-4gib-sfo3-01:~# diff -U3 /tmp/1 /tmp/2 --- /tmp/1 2020-12-01 01:07:39.795361392 +0000 +++ /tmp/2 2020-12-01 01:07:51.991808848 +0000 @@ -1,6 +1,6 @@ local fe80::8466:b3ff:fecc:3a4f dev r0_v01 table 10 proto kernel metric 0 pref medium local fe80::b4ec:a8ff:fec3:33d9 dev r0_v00 table 10 proto kernel metric 0 pref medium -fe80::/64 dev r0_v00 table 10 proto kernel metric 256 pref medium fe80::/64 dev r0_v01 table 10 proto kernel metric 256 pref medium -ff00::/8 dev r0_v00 table 10 metric 256 pref medium +fe80::/64 dev r0_v00 table 10 proto kernel metric 256 pref medium ff00::/8 dev r0_v01 table 10 metric 256 pref medium +ff00::/8 dev r0_v00 table 10 metric 256 pref medium With your patch does ping from both hosts work? What about all of the tests in tools/testing/selftests/net/fcnal-test.sh? specifically curious about the 'LLA to GUA' tests (link local to global). Perhaps those tests need a second interface (e.g., a dummy) that is brought up first to cause the ordering to be different.
