Руководство По Проектированию для Cisco Cisco Nexus 5010 Switch

Design Guide

Page 17 of 38

vPC Reload Restore

The vPC reload restore feature was introduced with Cisco NX-OS 5.0(2). With vPC reload restore, when the peer

link is down, or when the both peer link and peer-keepalive links are lost, the vPC primary can activate new vPCs

ports.

If the vPC peer switch is brought online or connected to the existing vPC peer switch, the configuration checks are

performed; if inconsistencies are found, the vPC ports are shut down.

In addition, with reload restore a vPC peer can reload, and after a reload, if no vPC peer exists (a condition that is

detected by a timer), the user can create vPCs on the standalone vPC peer.

Upon reload, Cisco NX-OS starts a user-configurable timer (with a default of 240 seconds). If the peer-link port

comes up physically or if the peer keepalive is functional, the timer is stopped and the device waits for the peer

adjacency to form. If at timer expiration no peer-keepalive- or peer-link-up packets have been received, Cisco NX-OS

assumes the primary role. The software reinitializes the vPCs, activating its local ports. Because there are no peers,

the consistency check is bypassed for the local vPC ports.

The timer is user configurable and defines how long the standalone vPC device waits to detect a vPC peer. If at the

timer expiration no peer-keepalive- or peer-link-up packets have been received, the software reinitializes the vPCs,

activating its local ports. Because there are no peers, the consistency check is bypassed for the local vPC ports.

The following output shows the status of a virtual PortChannel configured on a standalone vPC system with restore

reload:

----------------------------------------------------------------------

id Port Status Consistency Reason Active vlans

-- ---- ------ ----------- -------------------------- ------------

51 Po51 up success Type checks were bypassed 10-14, 21-24

for the vPC ,50,60

vPC Configuration Consistency

The Ethernet PortChannel capability allows links to be bundled to form a single entity if certain compatibility

conditions are met. The following is a list of conditions that are verified before ports can form a regular PortChannel

(this list refers to regular PortChannels, not vPCs specifically). Members must:

●

Have the same port mode configured

●

Have the same speed configured; if they are configured with speed AUTO, they have to negotiate the same

speed when they become active, and if a member negotiates a different speed, it will be suspended

●

Have the same maximum transmission unit (MTU) value configured

●

Have the same duplex mode configured

●

Have the same Ethernet layer (switchport or no switchport) configured

●

Not be SPAN ports

●

Have the same storm control configured

●

Have the same flow control configured

●

Have common capabilities

●

Be switching ports (Layer 2)

●

Have the same port access VLAN

●

Have the same port native VLAN

●

Have the same port-allowed VLAN list