Cisco Systems 6500 Switch User Manual


  Open as PDF
of 1600
 
2-469
Catalyst 6500 Series Switch Command Reference—Release 8.6
OL-8977-01
Chapter 2 Catalyst 6500 Series Switch and ROM Monitor Commands
set mls agingtime
The fastagingtime value can be configured in the range of 0 to 128 seconds.
The default pkt_threshold value is 0. If you do not configure fastagingtime exactly the same for these
values, it adjusts to the closest value. A typical value for fastagingtime and pkt_threshold is 32 seconds
and 0 packet, respectively. (It means no packet switched within 32 seconds after the entry was created.)
The agingtime value applies to an MLS entry that has no more than pkt_threshold packets switched
within fastagingtime seconds after it is created. A typical example is the MLS entry destined to or
sourced from a DNS or TFTP server. This entry may never be used again once it is created. For example,
only one request goes to a server and one reply returns from the server, and then the connection is closed.
The agingtime fast option is used to purge entries associated with very short flows, such as DNS and
TFTP.
Keep the number of MLS entries in the MLS cache below 32,000. If the number of MLS entries exceed
32,000, some flows (less than 1 percent) are sent to the router.
To keep the number of MLS cache entries below 32,000, decrease the aging time up to 8 seconds. If your
switch has a lot of short flows used by only a few packets, then you can use fast aging.
If cache entries continue to exceed 32,000, decrease the normal aging time in 64-second increments from
the 256-second default.
You can force an active flow to age out by entering the set mls agingtime long-duration command. You
can specify the aging time of the active flow in the range of 64 to 1920 seconds in increments of 64.
Examples These examples show how to set the aging time:
Console> (enable) set mls agingtime 512
IP Multilayer switching aging time set to 512 seconds.
Console> (enable)
This example shows how to set the fast aging time:
Console> (enable) set mls agingtime fast 32 0
Multilayer switching fast aging time set to 32 seconds for entries with no more than 0
packet switched.
Console> (enable)
This example shows how to set the aging time for active flows:
Console> (enable) set mls agingtime long-duration 128
Multilayer switching agingtime set to 128 seconds for long duration flows
Console> (enable)
Related Commands clear mls statistics entry
show mls