What is your ping to the device behind this 4210 unit?
Even if 2000ms sounds odd getting high "ping" from a single unit isnt that odd if the hop next in line is normal.
However unusual high pings from a single unit could be due to some kind of network loop hitting the mgmt plane too much (or other continues changes in the network so the routingtable and/or spanning tree must be recalced all the time).
Dunno about commands but what about looking at cpu usage?
Try this command:
display cpu-usage history
The cpu usage should be around 15-20% (from my own experience with 5820 and 5120EI devices).