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Catalyst 2950 Desktop Switch Software Configuration Guide
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Chapter 26 Configuring QoS Configuring QoS
To delete an existing policy map, use the no policy-map policy-map-name global configuration
comm and. To de lete an exist ing class ma p, use the no class class-map-name policy-ma p co nfigurat ion
command. To remove an assigned DSCP value, use the no set ip dscp new-dscp policy-map
configurat ion c omm and. To remove an exi stin g p oli cer, use th e no police rate-bps burst-byte
[exceed-act ion {drop | dscp dscp-value}] policy-map configuration command. To remove the policy
map and in terface a ssociation, us e the no service-policy input policy-map-name interfa ce config uration
command.
This e xample sho ws ho w to create a polic y map and attach it to an ingress i nterface. I n the conf iguration,
the IP standard ACL permits traffic from network 10 .1.0.0. For traffic matching this classification, the
DSCP value in the incoming packet is trusted. If the matched traffic exceeds an average traffic rate
of 5000000 bps and a normal burst size of 8192 bytes, its DSCP is marked down to a v alue of 10 and sent.
Step 5 set { ip dscp new-dscp} Classify IP traffic by setting a new value in the packet.
For ip dscp new-dscp, enter a new DSCP value to be assigned to the
classified t raffic. The s uppo rt ed D SCP values a re 0 , 8, 10, 1 6, 18 , 24,
26, 32, 3 4, 40, 4 6, 48 , an d 5 6.
Step 6 police rate-bp s burst-byte [exceed-action
{drop | dscp dscp-value}] Define a policer for th e class ified tra ffi c.
You can configure up to 60 polic ers on ingress Giga bit-cap able
Ethernet ports and up to 6 policers on ingress 10/100 Ethernet ports.
For rate-bps, specify average traffic rate in bits per second (bps). The
range i s 1 Mbps to 100 Mbps for 10/10 0 Et hern et ports and 8 Mb ps to
1000 Mb ps for the Gigabi t-cap able Ethe rnet por ts.
For burst-byte, spe cif y the n orma l burs t size in bytes. The va lue s
support ed on t he 1 0/100 p ort s ar e 409 6, 81 92, 1 638 4, 327 68, and
65536. The values supported on the Gigabit-capable Ethernet ports are
4096, 8 192, 1 6348, 32 768 , 65536, 13 107 2, 26 2144 , an d 524288.
(Optional) Specify the action to take when the rates are exceeded. Use
the exceed-action drop keywords to drop the packet . Use the
exceed-act ion dscp dscp-value keywords to ma rk down t he D SCP
value and send the packet.
Step 7 exit Return to policy-map configuration mode.
Step 8 exit Return to glob al co nfiguration mo de.
Step 9 int er fa ce interface-id Enter interface configuration mode, and specify the interface to attach
to th e po licy map .
Valid interfaces include physical interfaces.
Step 10 service-policy input policy-map-name Apply specified policy map to the inpu t of a particul ar inter face.
Only one pol icy map per inter face per direct ion is supp orted.
Step 11 end Return to privileged EXEC mode.
Step 12 show policy-map [policy-map-name class
class-name]Verify your entries.
Step 13 copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose