About QoS TCAM Carving
You can change the size of the access control list (ACL) ternary content addressable memory (TCAM) regions in the hardware.
On Cisco Nexus 9300 and 9500 platform switches and Cisco Nexus 3164Q, 31128PQ, 3232C, and 3264Q switches, the egress TCAM size is 1K, divided into four 256 entries. On Cisco Nexus NFE2-enabled devices (such as the Cisco Nexus 3232C and 3264Q switches), the ingress TCAM size is 6K, divided into twelve 512 slices. Three slices are in one group. On other Cisco Nexus 9300 and 9500 platform switches and Cisco Nexus 3164Q and 31128PQ switches, the ingress TCAM size is 4K, divided into eight 256 slices and four 512 slices. A slice is the unit of allocation. A slice can be allocated to one region only. For example, a 512-size slice cannot be used to configure two features of size 256 each. Similarly, a 256-size slice cannot be used to configure two features of size 128 each. The IPv4 TCAM regions are single wide. The IPv6, QoS, MAC, CoPP, and system TCAM regions are double wide and consume double the physical TCAM entries. For example, a logical region size of 256 entries actually consumes 512 physical TCAM entries.
On Cisco Nexus 9200 Series switches, the egress TCAM size is 2K, and the ingress TCAM size is 4K. The concepts of TCAM slices and single- and double-wide regions do not apply to these switches. For example, the ing-ifacl region can host IPv4, IPv6, or MAC type entries. IPv4 and MAC types occupy one TCAM entry whereas IPv6 types occupy two TCAM entries.
The number of default entries for QoS TCAM carving are:
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The default QoS TCAM carving for the Cisco Nexus 9504, Cisco Nexus 9508, and Cisco Nexus 9516 is for Layer 3 QoS (IPV4) with 256 entries. For these switches, all of the QoS TCAM entries are double wide.
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The default QoS TCAM carving for ALE (Application Leaf Engine) enabled devices is for Layer 2 port QoS (IPV4) with 256 entries. For these switches, all of the QoS TCAM entries are double wide.
Note |
In addition to the above TCAM, for ALE enabled devices, a separate TCAM in the Cisco Nexus C9396PX (uplink ports) and Cisco Nexus C93128TX (uplink ports) ASIC is used for the QoS classification policies applied on 40G uplink ports. By default, this separate TCAM is carved for Layer 3 QoS (IPV4), Layer 2 Port QoS (IPV4), and VLAN QoS (IPV4) with 256 entries each. |
Feature |
Purpose |
Region Name |
---|---|---|
Egress QoS |
QoS policy applied on interfaces in output direction. |
IPV4: e-qos Cisco Nexus 922 series switch: egr-l2-qos, egr-l3-vlan-qos IPV6: e-ipv6-qos MAC: e-mac-qos See notes following table. |
Feature |
Purpose |
Region Name |
---|---|---|
Layer 3 QoS |
QoS policy applied on Layer 3 interfaces. |
IPV4: l3qos*, ns-l3qos* IPV6: ipv6-l3qos*, ns-ipv6-l3qos* See notes following table. |
Port QoS |
QoS policy applied on Layer 2 interfaces. |
IPV4: qos*, ns-qos* IPV6: ipv6-qos*, ns-ipv6-qos* MAC: mac-qos*, ns-mac-qos* See notes following table. |
VLAN QoS |
QoS policy applied on VLAN. |
IPV4: vqos, ns-vqos IPV6: ipv6-vqos*, ns-ipv6-vqos* MAC: mac-vqos*, ns-mac-vqos* See notes following table. |
FEX QoS |
QoS policy applied on FEX interfaces. |
IPV4: fex-qos* IPv6: fex-ipv6-qos* MAC: fex-mac-qos* See notes following table. |
Feature |
Purpose |
Region Name |
---|---|---|
Layer 3 QoS |
QoS policy applied on Layer 3 interfaces. |
IPV4: l3qos*, ns-l3qos*, rp-qos** Cisco Nexus 9200 Series switch: ing-l3-vlan-qos IPV6: ipv6-l3qos*, ns-ipv6-l3qos*, rp-ipv6-qos** See notes following table. |
Port QoS |
QoS policy applied on Layer 2 interfaces. |
IPV4: qos*, ns-qos*, rp-qos** Cisco Nexus 9200 Series switch: ing-l2-qos IPV6: ipv6-qos*, ns-ipv6-qos*, rp-ipv6-qos** MAC: mac-qos*, ns-mac-qos*, rp-mac-qos** See notes following table. |
VLAN QoS |
QoS policy applied on VLAN. |
IPV4: vqos, ns-vqos, rp-qos** Cisco Nexus 9200 Series switch: ing-l3-vlan-qos IPV6: ipv6-vqos*, ns-ipv6-vqos*, rp-ipv6-qos** MAC: mac-vqos*, ns-mac-vqos*, rp-mac-qos** See notes following table. |
FEX QoS |
QoS policy applied on FEX interfaces. |
IPV4: fex-qos* IPv6: fex-ipv6-qos* MAC: fex-mac-qos* See notes following table. |
Note |
* The region is applicable only for ALE enabled devices and are required for classification policies applied on 40G uplink ports. |
Note |
** The region is applicable only for 100G enabled devices (such as the Cisco Nexus 9300 platform switch with the N9K-M4PC-CFP2 GEM or the Cisco Nexus 9500 platform switch with the Cisco Nexus 9408PC-CFP2 line card) and are required for classification policies and QoS scheduling applied on 100G uplink ports. |
You need to save the configuration and reload the system for the region configuration to become effective.
About QoS TCAM Lite Regions
IPV4 requires QoS TCAM regions to be double wide TCAMs to support conform/violate policer statistics. If conform/violate statistics are not required, the size of the QoS TCAM entries can be reduced to single wide TCAMs by using QoS TCAM lite regions. Policing is supported by these regions, however only violate packets/bytes statistics are supported.
Feature |
Purpose |
Region Name |
---|---|---|
Egress QoS |
QoS policy applied on interfaces in output direction. |
IPV4: e-qos-lite See notes following table. |
Feature |
Purpose |
Region Name |
---|---|---|
Layer 3 QoS |
QoS policy applied on Layer 3 interfaces. |
IPV4: l3qos-lite |
Port QoS |
QoS policy applied on Layer 2 interfaces. |
IPV4: qos-lite |
VLAN QoS |
QoS policy applied on VLAN. |
IPV4: vqos-lite |
FEX QoS |
QoS policy applied on FEX interfaces. |
IPV4: fex-qos-lite |
Note |
Cisco Nexus 9200 Series switches do not support QoS TCAM lite regions. |
Note |
The region is applicable only for ALE enabled devices and are required for classification policies applied on 40G uplink ports. |
You need to save the configuration and reload the system for the region configuration to become effective.
Note |
Either the regular version or the lite version of the QOS TCAM can be enabled. Both cannot be enabled at the same time. For example, either the IPv4 Port QoS or the IPv4 Port QoS lite version can be enabled at any one time. |