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This chapter describes the Cisco NX-OS quality of service (QoS) commands that begin with M.
To identify a specified access control list (ACL) group as a match criteria for a class map, use the match access-group command. To remove an ACL match criteria from a class map, use the no form of this command.
match access-group name acl-name
no match access-group name acl-name
Class-map type qos configuration
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Note The permit and deny ACL keywords do not affect the matching of packets.
This example shows how to create a qos class map that matches characteristics of the ACL my_acl:
switch(
config)#
class-map class_acl
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To define the class of traffic using the class of service (CoS) value in a type qos class map, use the match cos command. To remove the match on the CoS value, use the no form of this command.
Specified CoS value or list of specified CoS values. Valid values are from 0 to 7. |
Class-map type qos configuration
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To specify a list of values, use one of the following options:
Note Only class maps of type qos support the optional not keyword form of this command. Class maps of type queuing do not support the not keyword.
This example shows how to match on the CoS value for a type qos class map:
switch(
config)#
class-map class_acl
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To identify specific differentiated services code point (DSCP) values in the DiffServ field of the IP Header (either IPv4 or IPv6) as a match criteria, use the match dscp command. To remove specified DSCP values as a match criteria, use the no form of this command.
no match [ not ] dscp dscp-list
Specified DSCP value or list of DSCP values. See Table 1 for a list of valid DSCP values. |
Class-map type qos configuration
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The standard DSCP values are shown in Table 1 .
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To specify a list of values, use one of the following options:
This example shows how to match on DSCP value af21:
switch(
config)#
class-map my_test
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To configure a class map to use the Real-Time Protocol (RTP) port as a match criteria, use the match ip rtp command. To remove the RTP port as a match criteria, use the no form of this command.
match [ not ] ip rtp port-list
no match [ not ] ip rtp port-list
Specified UDP port or list of UDP ports that are using RTP. Valid values range from 2000 to 65535. |
Class-map type qos configuration
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To specify a list of values, use one of the following options:
This example shows how to match on a port using RTP:
switch(
config)#
class-map my_test
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To configure a class map to use the precedence value in the type of service (ToS) byte field of the IP header (either IPv4 or IPv6) as a match criteria, use the match precedence command. To remove the precedence values as a match criteria, use the no form of this command.
match [ not ] precedence precedence-list
no match [ not ] precedence precedence-list
Specified IP precedence value or list of IP precedence values specified in bytes. Valid values are shown in Table 2 . |
Class-map type qos configuration
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See Table 2 for a list of precedence values.
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To specify a list of values, use one of the following options:
This example shows how to match on an IP precedence value:
switch(
config)#
class-map my_test
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To configure a class map to use a specific protocol as a match criterion, use the match protocol command. To remove the specified protocol as a match criteria, use the no form of this command.
match [ not ] protocol protocol-name
no match [ not ] protocol protocol-name
Specified protocol name. Valid values are shown in Table 3 . |
Class-map type qos configuration
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The list of valid protocol names is shown in Table 3 .
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To specify more than one protocol, enter the command more than once with the desired protocol value each time.
This example shows how to match on a specified protocol:
switch(
config)#
class-map my_test
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To configure a class map to use a specific QoS group value as a match criterion, use the match qos-group command. To remove the specified protocol as a match criteria, use the no form of this command.
match [ not ] qos-group qos-group-list
no match [ not ] qos-group qos-group-list
Specified Qos group value or list of QoS group values specified in bytes. Valid values are from 2 to 5. |
Class map type network-qos configuration
Class map type queuing configuration
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The QoS group is an internal label and is not part of the packet payload or any packet header. The QoS group values have no mathematical significance. For example, a QoS group value of 2 is not greater than 1; the values are used only to internally differentiate QoS groups. As such, this value has local significance only.
You match on the QoS group only in egress policies because its value is undefined until you set it in an ingress policy.
To specify a list of values, use one of the following options:
This example shows how to match on a specified QoS group value:
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To set the maximum transmission unit (MTU) size for Encapsulated Remote Switched Port Analyzer (ERSPAN) packets in a monitor session, use the mtu command. To remove the configured MTU, use the no form of this command.
Maximum allowable MTU for ERSPAN packets in a monitor session. The range is from 64 to 1518 bytes. |
ERSPAN session configuration mode
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ERSPAN packets larger than the specified allowable size for the monitor session are truncated.
This example shows how to set an MTU value for an ERSPAN session:
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To configure the maximum transmission unit (MTU) size for Layer 2 and Layer 3 Ethernet interfaces, use the mtu command. To remove the configured MTU, use the no form of this command.
MTU value for the class of service (CoS). The range is from 64 to 9216.1500 to 9216. |
Default MTU value is 1500. For FCoE cos 3, the default is 2158.
Policy map type network-qos class configuration
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The MTU range is changed to 1500 to 9216. Note On a Cisco Nexus 5000 Series that run a Cisco NX-OS Release 4.1(3)N2(1) or earlier releases, the MTU range is from 1538 to 9216. |
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You can configure an MTU for each virtual link in the system.
This example shows how to set an MTU value for a class in a type network-qos policy map:
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To optimize a class to send multiple packets, use the multicast-optimize command.
Policy map type network-qos class configuration
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Multicast traffic in a class will be served by all available multicast queues.
Only one class in a policy map can be configured for multicast optimization.
Note On a Cisco Nexus 5548 switch, multicast optimization is enabled by default on the class-default class. You must remove it from the class-default class before enabling it on a user-defined class.
This example shows how to enable optimized multicast for a traffic class:
This example shows how to remove the multicast optimization from a traffic class:
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