D-Link DGS-6600-48T Cli Reference Manual page 629

DGS-6604 m
UpTime
ExpTime
Generation ID
CLI Reference Guide
The total time elapsed since the neighbor was discoved until now.
The time remaining until the entry is removed from the DVMRP neighbor
table.
If a DVMRP router is restarted, it will not be aware of any previous prunes
that it had sent or received. In order for the neighbor to detect that the
router has restarted, a non-decreasing number is placed in the periodic
probe message called the generation ID. When a change in the generation
ID is detected, any prune information received from the router is no longer
valid and should be flushed.
show ip dvmrp neighbor
619