Motorola BSR 64000 Reference Manual page 824

BSR 64000 Command Reference Guide
The following table describes a list of possible SPF triggers
Trigger
PERIODIC
NEWSYSID
NEWAREA
NEWLEVEL
NEWMETRIC
IPBACKUP
IPQUERY
ATTACHFLAG
ADMINDIST
AREASET
NEWADJ
DBCHANGED
BACKUPOVFL
NEWLSP
LSPEXPIRED
LSPHEADER
18-42
Reason
Typically, every 15 minutes a router runs a periodic full SPF
calculation.
A new system ID through the NET was configured on this router.
A new area (via NET) was configured on this router.
A new level (via is-type) was configured on this router.
A new metric was configured on an interface of this router.
An IP route disappeared, which was not learned via IS-IS, but via
another protocol with better administrative distance. IS-IS will run
a full SPF to install an IS-IS route for the disappeared IP prefix.
A clear ip route command was issued on this router.
This router is now attached to the Level 2 backbone or it has just
lost contact to the Level 2 backbone.
Another administrative distance was configured for the IS-IS
process on this router.
Set of learned area-addresses in this area changed.
This router has created a new adjacency to another router.
A clear isis * command was issued on this router.
An IP prefix disappeared. The router knows there is another way
to reach that prefix, but has not stored that backup route. The only
way to find the alternative route is to run a full SPF run.
A new router or pseudonode appeared in the topology.
Some LSP in the LSDB has expired.
ATT/P/OL bits or is-type in an LSP header changed.