Pending requests are those that have been sent to the agent but no response has yet been received back. Sometimes it is desireable to cancel pending requests if, for example, session configuration has changed or it is determined that no response will be received before the timeout occurs.
% snmpcmd cancel ?id ...?
snmpcmd
id
% foreach id [$sess pending] { $sess cancel $id }
...or...
% eval $sess cancel [$sess pending]
% $sess cancel {expand}[$sess pending]