R2511-HP MSR Router Series Network Management and Monitoring Configuration Guide(V5)
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• Forced aging
• TCP FIN- and RST-triggered aging (automatically tr
iggered if a TCP connection is terminated)
Periodical aging
Periodical aging uses the following approaches:
• Inactive flow aging—A flow is considered inactive if its statistics have not been changed, which
means no packet for this NetStream entry arrives in the time specified by the ip netstream timeout
inactive command. The inactive flow entry remains in the cache until the inactive timer expires. Then
the inactive flow is aged out and its statistics, which can no longer be displayed by the display ip
netstream cache command, are sent to the NetStream server. The inactive flow aging makes sure
that the cache is big enough for new flow entries.
• Active flow aging—An active flow is aged out when the time specified by the ip netstream timeout
active command is reached, and its statistics are exported to the NetStream server. The device
continues to count the active flow statistics, which can be displayed by the display ip netstream
cache command. The active flow aging exports the statistics of active flows to the NetStream server.
Forced aging
Use the reset ip netstream statistics command to age out all NetStream entries in the cache and to clear
the statistics. This is forced aging.
TCP FIN- and RST-triggered aging
For a TCP connection, when a packet with a FIN or RST flag is sent out, it means that a session is finished.
If a packet with a FIN or RST flag is recorded for a flow with the NetStream entry already created, the
flow is aged out immediately. However, if the packet with a FIN or RST flag is the first packet of a flow,
a new NetStream entry is created instead of being aged out. This type of aging is enabled by default,
and it cannot be disabled.
Configuration procedure
To configure flow aging:
Ste
p
Command
Remarks
1. Enter system view.
system-view N/A
2. 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
Optional.
By default:
• The aging timer for active
flows is 30 minutes.
• The aging timer for
inactive flows is 30
seconds.