216
•
Inactive flow aging
—A flow is inactive if no packet arrives for this NetStream entry within the
period specified by using the
ip netstream timeout inactive
command. When the inactive flow
aging timer expires, the following situations occur:
{
The inactive flow entry is aged out.
{
The statistics of the flow are sent to NetStream servers. The statistics can no longer be displayed
by using the
display ip netstream cache
command.
When you use the inactive flow aging method, the cache is large enough for new flow entries.
•
Active flow aging
—A flow is active if packets arrive for the NetStream entry within the period
specified by using the
ip netstream timeout active
command. When the active flow aging timer
expires, the statistics of the active flow are exported to NetStream servers. The device continues to
collect active flow statistics, which can be displayed by using the
display ip netstream cache
command. The active flow aging method periodically exports the statistics of active flows to
NetStream servers.
Forced aging
To implement forced aging, use one of the following commands:
•
Use the
reset ip netstream statistics
command. This command ages out all NetStream entries, and
exports and clears the statistics.
•
Use the
ip netstream max-entry
command. This command provides the following processing
options when the upper limit is reached:
{
Age out the entries.
{
Disable creation of a new entry in the cache.
TCP FIN- and RST-triggered aging
TCP FIN- and RST-triggered aging is automatically performed when a TCP connection is terminated.
A TCP connection is terminated when a packet with a FIN or RST flag is received.
When a packet with a FIN or RST flag is recorded for a flow with an existing NetStream entry, the entry
is immediately aged out, exported, and cleared.
However, when the first packet of a flow has a FIN or RST flag, a new NetStream entry is created instead
of being aged out. This type of aging is always enabled, and it cannot be disabled.
Configuration procedure
To configure flow aging:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
(Optional.) Configure
periodical aging.
•
Set the aging timer for active flows:
ip netstream timeout active
minutes
•
Set the aging timer for inactive flows:
ip netstream timeout inactive
seconds
By default:
•
The aging timer for active
flows is 30 minutes.
•
The aging timer for
inactive flows is 30
seconds.
