About Reflective Relay 802.1Qbg - Cisco Nexus 9000 Series Configuration Manual

Configuring Reflective Relay for Layer2
Switching
This chapter contains the following sections:
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About Reflective Relay 802.1Qbg

Beginning with Cisco Nexus Release 7.0(3)I7(1), Cisco Nexus N9K-C93180XX-EX switches support the
switching option, reflective relay. This feature is a tagless approach of IEEE standard 802.1Qbg. It forwards
all traffic to an external switch that applies policy and sends the traffic back to the destination or target VM
on the server as needed. There is no local switching. For broadcast or multicast traffic, reflective relay provides
packet replication to each VM locally on the server.
Reflective relay leverages the external switch for switching features and management capabilities, freeing
server resources to support the VMs. Reflective relay applies the policies you configure on the Cisco Nexus
N9K-C93180XX-EX switch to traffic between the VMs on the same server.
You can enable reflective relay to turn back traffic out of the same port it came in on. You can enable reflective
relay on a Layer 2 physical port or port-channel interface policy using the NX-OS CLI. This feature is disabled
by default.
The term Virtual Ethernet Port Aggregator (VEPA) is also used to describe 802.1Qbg functionality.
Reflective Relay Support
Reflective relay supports the following:
• Cisco Nexus N9K-C93180XX-EX switches.
• IEEE standard 802.1Qbg tagless approach, known as reflective relay. However, Cisco Nexus Release
About Reflective Relay 802.1Qbg, page 179
Guidelines and Limitations for Reflective Relay, page 180
Configuring Reflective Relay Using the NX-OS CLI, page 180
7.0(3)I7(1) does not support the IEEE standard 802.1Qbg S-tagged approach with multichannel
technology.
Cisco Nexus 9000 Series NX-OS Layer 2 Switching Configuration Guide, Release 7.x
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