Cfsoe; Vpc Guidelines And Limitations - Cisco AP775A - Nexus Converged Network Switch 5010 Configuration Manual

CFSoE

You must configure a list of parameters to be identical on the vPC peer switches on both sides of the vPC
peer link.
STP is distributed; that is, the protocol continues running on both vPC peer switches. However, the configuration
on the vPC peer switch elected as the primary switch controls the STP process for the vPC interfaces on the
secondary vPC peer switch.
The primary vPC switch synchronizes the STP state on the vPC secondary peer switch using Cisco Fabric
Services over Ethernet (CFSoE).
The vPC manager performs a proposal/handshake agreement between the vPC peer switches that sets the
primary and secondary switches and coordinates the two switches for STP. The primary vPC peer switch then
controls the STP protocol for vPC interfaces on both the primary and secondary switches. We recommend
that you configure the primary vPC peer switch as the highest STP root priority, and configure the secondary
switch with a lower root priority.
If the primary vPC peer switch fails over to the secondary vPC peer switch, there is no change in the STP
topology.
The Bridge Protocol Data Units (BPDUs) use the MAC address set for the vPC for the STP bridge ID in the
designated bridge ID field. The vPC primary switch sends these BPDUs on the vPC interfaces.
Display the configuration on both sides of the vPC peer link to ensure that the settings are identical. Use
Note
the show spanning-tree command to display information about the vPC.
CFSoE
The Cisco Fabric Services over Ethernet (CFSoE) is a reliable state transport mechanism that you can use to
synchronize the actions of the vPC peer devices. CFSoE carries messages and packets for many features linked
with vPC, such as STP and IGMP. Information is carried in CFS/CFSoE protocol data units (PDUs).
When you enable the vPC feature, the device automatically enables CFSoE, and you do not have to configure
anything. CFSoE distributions for vPCs do not need the capabilities to distribute over IP or the CFS regions.
You do not need to configure anything for the CFSoE feature to work correctly on vPCs.
You can use the show mac address-table command to display the MAC addresses that CFSoE synchronizes
for the vPC peer link.
Do not enter the no cfs eth distribute or the no cfs distribute command. CFSoE must be enabled for
Note
vPC functionality. If you do enter either of these commands when vPC is enabled, the system displays an
error message.
When you enter the show cfs application command, the output displays "Physical-eth," which shows the
applications that are using CFSoE.

vPC Guidelines and Limitations

vPC has the following configuration guidelines and limitations:
• You must enable the vPC feature before you can configure vPC peer-link and vPC interfaces.
• You must configure the peer-keepalive link before the system can form the vPC peer link.
Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
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vPC Guidelines and Limitations
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