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Catalyst 6500 Series Switch Command Reference—Release7.6
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Chapter2 Catalyst 6500 Series Switch and ROM Monitor Commands set mls agingtime
If you enter any of the set mls commands on a Catalyst 6500 series switch without MLS, this warning
message displays:
MLS not supported on feature card.
The agingtime value can be configured as multiples of 8 in the range of 8 to 2024seconds. The values
are picked up in numerical order to achieve efficient aging. Any value for agingtime that is not a multiple
of 8 seconds is adjusted to the closest one. For example, 65 is adjusted to 64, while 127 is adjusted to
128.
The fastagingtime value can be configured as multiples of 8 to any value in the range of 0 to 128 seconds.
The default pkt_threshold value is 0. It can be configured as 0, 1 , 3, 7, 1 5, 31 , 6 3, or 1 27 (the values
picked for efficient aging). 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 32seconds 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/sourced
from a DNS or TFTP server. This entry may never be used again once it is create d. For exampl e, 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 entrie s belo w 32,0 00, decr ease the aging t ime up t o 8 seco nds. 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-se cond increment s from
the 256-second default.
You can force an active flo w to age out b y ente ring th e set mls agingtime long-d uration 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)
Console> (enable) set mls agingtime ipx 512
IPX Multilayer switching aging time set to 512
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)