H3C Technologies H3C S12500 Series Switches - Manual (Page 165)

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Configuring fast forwarding
The device operates in IRF or standalone (the default) mode. For information about IRF mode, see IRF
Configuration Guide.
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Overview
Fast forwarding reduces route lookup time and improves packet forwarding efficiency by using a
high-speed cache and data-flow-based technology. It uses a five-tuple (source IP address, source port
number, destination IP address, destination port number, and protocol number) to identify a data flow.
After the first packet of a flow is forwarded through the routing table, fast forwarding creates an entry for
the flow and uses the entry to forward subsequent packets of the flow.
Some features, such as packet queue management and header compression, can reduce fast forwarding
performance.
Fast forwarding can process fragmented IP packets, but it does not fragment IP packets.
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Configuration procedure
To configure fast forwarding:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enable fast forwarding. ip fast-forwarding By default, fast forwarding is enabled.
3. Configure the aging time of
fast forwarding entries. ip fast-forwarding aging-time
aging-time By default, the aging time is 30
seconds.
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Displaying and maintaining fast forwarding
Execute display commands in any view and reset commands in user view.
Task Command
Display fast forwarding table information (in
standalone mode). display ip fast-forwarding cache [ ip-address ] [ slot
slot-number ]
Display fast forwarding table information (in IRF
mode). display ip fast-forwarding cache [ ip-address ]
[ chassis chassis-number slot slot-number ]
Display fast forwarding table information about
fragmented packets (in standalone mode). display ip fast-forwarding fragcache [ ip-address ]
[ slot slot-number ]
Display fast forwarding table information for
fragmented packets (in IRF mode). display ip fast-forwarding fragcache [ ip-address ]
[ chassis chassis-number slot slot-number ]
Display the aging time of fast forwarding entries. display ip fast-forwarding aging-time