Some computer network equipment use the term "loopback" for a virtual interface used for management purposes.

Job meant your main normal IPv4 address, not the loopback address on the loopback virtual interface.

-- Wilco

On 20/03/15 09:23, olivier a wrote:

let's 192.168.1.1 is my router Wan IP. One single physical router running bird and bird6.

Solution 1 :
bird router id = 192.168.1.1
bird6 router id = 192.168.1.1

Solution 2 :
bird router id = 192.168.1.1
bird6 router id = 127.0.0.1

Is that what you're advising ?
What are the benefits of using IPv4 loopback as bird6 router id ??!
:-)

On Mar 19, 2015 11:13 AM, "Job Snijders" <job@instituut.net> wrote:
On Thu, Mar 19, 2015 at 11:08:06AM +0100, Ondrej Zajicek wrote:
> On Thu, Mar 19, 2015 at 09:35:42AM +0100, olivier a wrote:
> > Is it good practice to use same router id for bird and bird6 ?
> >
> > I'm wondering if there are some drawbacks or pitfalls ?
>
> I see no reason why not to use the same router id.

I second that. If they are the same physical box, using the IPv4
loopback as router-id in bird6 is a good (and common) approach.

Kind regards,

Job