Cisco Catalyst 4500 Series - Qos Account Layer2 Encapsulation

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Catalyst 4500 Series Switch Cisco IOS Command Reference—Release IOS XE 3.4.0SG and IOS 15.1(2)SG)
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Chapter 2 Cisco IOS Commands for the Catalyst 4500 Series Switches
qos account layer2 encapsulation
qos account layer2 encapsulation
To include additional bytes to be accounted by the QoS features, use the qos account layer2
encapsulation command. To disable the use of additional bytes, use the no form of this command.
qos account layer2 encapsulation {arpa | dot1q | isl | length len}
no qos account layer2 encapsulation {arpa | dot1q | isl | length len}
Syntax Description
Defaults On Supervisor Engine 6E, Supervisor Engine 6L-E, Catalyst 4900M, and Catalyst 4948-E, the length
that is specified in the Ethernet header is considered for both IP and non-IP packets. The Layer 2 length
includes the VLAN tag overhead.
Command Modes Global configuration mode
Command History
Usage Guidelines On Supervisor Engine 6E, Supervisor Engine 6L-E, Catalyst 4900M, and Catalyst 4948-E, shaping and
sharing always use Ethernet ARPA length to which 20 bytes of IPv6 overhead is always added for
policing. However, only Layer 2 length including VLAN tag overhead is considered.
Note The given length is included when policing all IP packets irrespective of the encapsulation with which
it was received. When qos account layer2 encapsulation isl is configured, a fixed length of 48 bytes is
included when policing all IP packets, not only those IP packets that are received with ISL encapsulation.
Sharing and shaping use the length that is specified in the Layer 2 headers.
Examples This example shows how to include an additional 18 bytes when policing IP packets:
Switch# config terminal
Switch(config)# qos account layer2 encapsulation length 18
Switch (config)# end
Switch#
arpa Specifies the account length of the Ethernet ARPA-encapsulated packet
(18 bytes).
dot1q Specifies the account length of the 802.1Q-encapsulated packet (22 bytes).
isl Specifies the account length of the ISL-encapsulated packet (48 bytes).
length len Specifies the a dditional packet length to account for; the valid range is from 0 to
64 bytes.
Release Modification
12.1(19)SG Support for this command was introduced on the Catalyst 4500 series switch.