OSPFv3 doesn't announce loopback IPv6 network

11 Dec 2022

      I want to use OSPF with BIRD v2.0.10 on Linux.

That works well, except that the IPv6 network of the lo interface isn't 
announced on OSPFv3. The IPv6 networks of the ethernet interfaces are 
announced as well as the IPv4 networks of all interfaces (ethernet and 
lo). The only missing is the IPv6 network of lo.

Here the OSPF config, really basic:

protocol ospf v2 {
   	ipv4 {
		import all;
		export all;
	};
	area 0 {
		interface "eth*" {
		};
		interface "lo" {
			stub;
		};
	};
}

protocol ospf v3 {
   	ipv6 {
		import all;
		export all;
	};
	area 0 {
		interface "eth*" {
		};
		interface "lo" {
			stub;
		};
	};
}

Without any active OSPF neighbor the routes show all interface networks 
except that of interface lo:

# birdc show route
BIRD 2.0.10 ready.
Table master4:
10.1.1.0/24          unicast [ospf1 17:03:20.860] * I (150/10) [3.3.3.3]
	dev eth0
10.1.2.0/24          unicast [ospf1 17:03:20.860] * I (150/10) [3.3.3.3]
	dev eth1
3.3.3.3/32           unicast [ospf1 17:03:20.860] * I (150/0) [3.3.3.3]
	dev lo

Table master6:
2001:1::/64          unicast [ospf2 17:03:25.861] * I (150/10) [3.3.3.3]
	dev eth0
2001:2::/64          unicast [ospf2 17:03:25.861] * I (150/10) [3.3.3.3]
	dev eth1

Here the configuration of interface lo:

# ip addr show dev lo
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN 
group default qlen 1000
     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
     inet 127.0.0.1/8 scope host lo
        valid_lft forever preferred_lft forever
     inet 3.3.3.3/32 scope global lo:1
        valid_lft forever preferred_lft forever
     inet6 2001::3/128 scope global
        valid_lft forever preferred_lft forever
     inet6 ::1/128 scope host
        valid_lft forever preferred_lft forever

What am I missing?

OSPFv3 doesn't announce loopback IPv6 network

Bernhard Ehlers