Cisco WS-X6248-RJ-45 - Catalyst 6000 Expansion Module Manual de usuario descargar pdf (Pagina 32)

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In CatOS, the policing parameters, such as rate, burst, and related actions, are deﬁned ﬁrst in a policer statement. A

QoS ACL is conﬁgured which identiﬁes both the trafﬁc to-be-policed and references the appropriate policer. Then,

the QoS ACL needs to be committed and applied to a port or VLAN, as with normal ACL conﬁguration.

In Cisco IOS Software, the ACL is deﬁned ﬁrst. The policing parameters are deﬁned in one of two conﬁgurations

modes. This depends on the type of policer being implemented and the speciﬁc differences are discussed in the

following sections.

Aggregate Policers

There are two forms of aggregate policers that can be deﬁned in the Cisco IOS Software: Shared Aggregate Policers

and Per-Interface Aggregate Policers.

Shared Aggregate Policers (sometimes referred to as Named Aggregate Policers) are applied to a group of interfaces/

VLANs and provide the function of policing trafﬁc across all interfaces and/or classes cumulatively. As an example,

use the shared aggregate policer when a 100-Mbps rate limit should be applied to four different interfaces combined.

These policers are supported in both CatOS and Cisco IOS Software. The following table shows a conﬁguration

comparison of the two implementations.

Note:

In CatOS, the rate is measured in Kbps and the burst is speciﬁed in Kb. In the Cisco IOS Software, the rate

is measured in bps and the burst is speciﬁed in bytes. These differences are true for all policer types.

Per-Interface Aggregate Policers are applied to an interface and trafﬁc class, individually. These policies can be

applied to multiple interfaces, but the policer polices each interface separately. As an example, use the Per Interface

Aggregate policer when a 100-Mbps rate limit should be applied individually to four different interfaces. These

policers are only supported in Cisco IOS Software

CatOS Cisco IOS Software

set qos policer aggregate ag1 rate

1000000 burst 32 drop

set qos acl ip ag_acl trust-dscp

aggregate ag1 any

set qos acl map ag_acl 3/5

access-list 101 permit ip any any

mls qos aggregate-policer ag1 10000000

4625 conform-action transmit exceed-

action drop

policy-map limit-named

class class-ag1 access-group 101

police aggregate ag1

interface fastethernet 3/5

service-policy input limit-named

4. Similar functionality can be achieved in CatOS, but it requires conﬁguring a unique policer for each interface in question. The Cisco IOS

implementation of per-interface policers requires that the policer is deﬁned only once, but applied separately.

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Cisco WS-X6248-RJ-45 - Catalyst 6000 Expansion Module Manual de usuario Pagina 32