Comment 22 for bug 1531013

Adding more info I identified for comment:

1) When adding the 53rd entry for multicast ethernet frames, it doubles all entries for multicast ethernet frames. After adding the 55th entry, it creates huge number of entries and it won't count the lines as a result. This also means we won't get the problem in environment with nodes <=52.

2) After applying 9063e21fb026c4966fc93261c18322214f9835eb to v3.13, the problem was gone.

root@vmtotest:~/fdb_bug# sudo bridge fdb append 00:00:00:00:00:00 dev vxlan1 dst 123.123.123.50 self permanent
root@vmtotest:~/fdb_bug# bridge fdb show | wc -l
55
root@vmtotest:~/fdb_bug# sudo bridge fdb append 00:00:00:00:00:00 dev vxlan1 dst 123.123.123.51 self permanent
root@vmtotest:~/fdb_bug# bridge fdb show | wc -l
56
root@vmtotest:~/fdb_bug# sudo bridge fdb append 00:00:00:00:00:00 dev vxlan1 dst 123.123.123.52 self permanent
root@vmtotest:~/fdb_bug# bridge fdb show | wc -l
57
root@vmtotest:~/fdb_bug# sudo bridge fdb append 00:00:00:00:00:00 dev vxlan1 dst 123.123.123.53 self permanent
root@vmtotest:~/fdb_bug# bridge fdb show | wc -l
111
root@vmtotest:~/fdb_bug# sudo bridge fdb append 00:00:00:00:00:00 dev vxlan1 dst 123.123.123.54 self permanent
root@vmtotest:~/fdb_bug# bridge fdb show | wc -l
112
root@vmtotest:~/fdb_bug# sudo bridge fdb append 00:00:00:00:00:00 dev vxlan1 dst 123.123.123.55 self permanent
root@vmtotest:~/fdb_bug# bridge fdb show | wc -l #hung