[j-nsp] Multiple loopback units

[Jose Sanchez]

Hi,

In the
http://www.juniper.net/techpubs/software/junos/junos80/swconfig80-vpns/html/vpnl3-config32.html#1072419

I can read the following text: For Layer 3 VPNs (VRF routing instances), you
can configure a logical unit on the loopback interface into each VRF routing
instance that you have configured on the router. Associating a VRF routing
instance with a logical unit on the loopback interface allows you to easily
identify the VRF routing instance.

What I tried to do is:
[edit interfaces lo0 unit 5 family inet]
router# commit
[edit interfaces lo0]
  'unit 5'


I got the following error:
    if_instance: Multiple loopback interfaces not permitted in master
routing instance
error: configuration check-out failed


How can I configure multiple loopback units, one for each vrf?

Thank you


Jose Sanchez