Two IPv4s lead to "Missing broadcast address for interface"?

[Robert Scheck]

Hello folks,

since upgrading from BIRD 2.0.2 to 2.0.4 I'm seeing the message "Missing
broadcast address for interface bond0" on one out of two systems in syslog
e.g. when starting BIRD.

System cr0 with "Missing broadcast address for interface bond0" is:

[root at cr0 ~]# ip a s bond0
10: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether xx:xx:xx:xx:xx:xx brd ff:ff:ff:ff:ff:ff
    inet 192.0.2.251/29 brd 192.0.2.255 scope global bond0
       valid_lft forever preferred_lft forever
    inet 192.0.2.249/29 scope global secondary bond0
       valid_lft forever preferred_lft forever
    inet6 2001:db8::1/64 scope global nodad 
       valid_lft forever preferred_lft forever
    inet6 2001:db8::3/64 scope global 
       valid_lft forever preferred_lft forever
    inet6 fe80::xxxx:xxxx:xxxx:xxxx/64 scope link 
       valid_lft forever preferred_lft forever
[root at cr0 ~]# 

System cr1 without "Missing broadcast address for interface bond0" is:

[root at cr1 ~]# ip a s bond0
10: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether xx:xx:xx:xx:xx:xx brd ff:ff:ff:ff:ff:ff
    inet 192.0.2.252/29 brd 192.0.2.255 scope global bond0
       valid_lft forever preferred_lft forever
    inet6 2001:db8::4/64 scope global 
       valid_lft forever preferred_lft forever
    inet6 fe80::xxxx:xxxx:xxxx:xxxx/64 scope link 
       valid_lft forever preferred_lft forever
[root at cr1 ~]# 

If I move the cluster/floating IPv4 address 192.0.2.249/29 using keepalived
from cr0 to cr1, then system cr1 shows the message and system cr0 is quiet.

Thus it feels like BIRD 2.0.4 tries to do some broadcast detection if there
are two IPv4 addresses from the same network on an interface? Might this be
related to the "bird 2.0.4 autodetects /30 as ptp" thread?


Regards,
  Robert