On 2021-12-17 18:26, Ondrej Zajicek wrote:
That is interesting. If i remember correctly, in the past Linux removed
all secondary addresses (ones from the same net) when the primary
address
was removed (so only addresses from other networks were considered
relevant).
Perhaps it was long before promote_secondary in sysctl was introduced.
So it is possible that Linux promotes an address to
primary, but does not sent a notification about that. Will check that.
Unlikely, then bird wouldn't see any addresses at all. This is what
happens on empty interface after adding few addresses and then deleting
primary:
# ip -d mon ad
2: enp6s20 inet 192.168.111.1/24 scope global enp6s20
valid_lft forever preferred_lft forever
2: enp6s20 inet 192.168.111.2/24 scope global secondary enp6s20
valid_lft forever preferred_lft forever
2: enp6s20 inet 192.168.111.3/24 scope global secondary enp6s20
valid_lft forever preferred_lft forever
2: enp6s20 inet 192.168.111.4/24 scope global secondary enp6s20
valid_lft forever preferred_lft forever
# Now deleting primary 192.168.111.1/24
Deleted 2: enp6s20 inet 192.168.111.1/24 scope global enp6s20
valid_lft forever preferred_lft forever
2: enp6s20 inet 192.168.111.2/24 scope global enp6s20
valid_lft forever preferred_lft forever
As you could see, primary is deleted but now next existing is announced
without "secondary" flag - I guess the problem is that flags are not
checked on updates thus existing addresses are simply ignored.
Perhaps another option would be to allow to use secondary addresses when
explicitly requested by "preferred" in device configuration (and this
makes sense), though this is more complicated to implement, of course.
Best regards,
Alexander.
