I created a vlan in Juniper qfx3600 switch by specifying just VLAN name. When I tried to commit the configuration I got an error saying "need L2domain configured". I asked with my collegue, he said you must provide vlan id, when I specified VLAN-id to the created vlan the commit was successful. But the documentations I read says VLAN automatically will be assosciated with VLAN ID if one is not provided by the user.
I got confused by all of these, can anyone please tell me which is right and why the commit was successfull after I provided VLAN ID but not before that.