Configuring netstream flow aging, Flow aging approaches, Periodical aging – H3C Technologies H3C MSR 50 User Manual
Page 114: Forced aging, Tcp fin- and rst-triggered aging

To configure MPLS-aware NetStream:
Step Command
Remarks
249.
Enter system view.
system-view
N/A
By default, no statistics about MPLS
packets are counted and exported.
The command of ip netstream mpls
[ label-positions { label-position1
[ label-position2 ]
[ label-position3 ] } ] [ no-ip-fields ]
enables both IPv4 and IPv6
NetStream of MPLS packets.
250.
Count and export
statistics on MPLS
packets.
ip netstream mpls [ label-positions
{ label-position1 [ label-position2 ]
[ label-position3 ] } ] [ no-ip-fields ]
Configuring NetStream flow aging
Flow aging approaches
The following types of NetStream flow aging are available:
•
•
TCP FIN- and RST-triggered aging (automatically triggered 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.
101