Hi Simon,
Not sure if it helps, but There's a default value in /etc/nav/ipdevpoll.conf, in section [job_inventory] interval: 6h
If you restart the ipdevpoll service, maybe it can force an update of the interface discovery ? command line:
nav restart ipdevpoll
You can also run the topology discovery of your vlans with the command navtopology --vlan
regards
Ludovic -- Ludovic Four Université de Strabourg Faculté de Pharmacie - Support Informatique Strasbourg - France