Bird 2.x / OSPF v3 over ptp tunnels

[Alarig Le Lay]

On mar. 11 févr. 18:27:43 2020, Joakim Tjernlund wrote:
> On Tue, 2020-02-11 at 18:18 +0100, Alarig Le Lay wrote:
> > CAUTION: This email originated from outside of the organization. Do
> > not click links or open attachments unless you recognize the sender
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> > 
> > 
> > Hi,
> > 
> > On mar. 11 févr. 17:52:29 2020, Bastien Durel wrote:
> > > 7: wg4b: <POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1420 state UNKNOWN qlen 1000
> > >     inet6 fe80::3/128 scope link
> > >        valid_lft forever preferred_lft forever
> > > 8: wg4a: <POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1420 state UNKNOWN qlen 1000
> > >     inet6 fe80::3/128 scope link
> > >        valid_lft forever preferred_lft forever
> > 
> > Don’t put fe80 addresses by hand and definitely not with /128, let your
> > kernel handles this.
> 
> I always wondered why not /128 ? In IPV4 they are just fine.

Because OSPF uses multicast. In IPv4 the route is implicitly on all
interfaces. With IPv6, it’s the link-local. So if your address is /128
no route is added, and multicast can’t work.

-- 
Alarig