Home » Cisco » 350-080 » Which two statements about virtual port channel graceful consistency checks are true?
Consistency checks and compatibility checks are performed before a vPC is created. During a compatibility check, one vPC peer conveys configuration information to the other vPC peer to verify that vPC member ports can actually form a port channel. Which two statements about virtual port channel graceful consistency checks are true? (Choose two.)
A. Graceful consistency check is enabled by default.
B. When graceful consistency check is enabled, only the links on the secondary peer device are suspended.
C. Graceful consistency check is disabled by default. To enable this feature, use the graceful consistency-check command under the vPC domain configuration mode.
D. When graceful consistency check is enabled, only the inconsistent VLANs on the secondary peer device are suspended.
E. Graceful consistency check is disabled by default.
Correct Answer: AB
Explanation/Reference:
Explanation:
Beginning with Cisco NX-OS Release 5.0(2)N2(1) and later releases, when a Type 1 mismatch occurs, by default, the primary vPC links are not suspended. Instead, the vPC remains up on the primary switch and the Cisco Nexus 5000 Series switch performs Type 1 configurations without completely disrupting the traffic flow. The secondary switch brings down its vPC until the inconsistency is cleared.
However, in Cisco NX-OS Release 5.0(2)N2(1) and earlier releases, this feature is not enabled for dual-homed FEX ports. When Type-1 mismatches occur in this topology, the VLANs are suspended on both switches. The traffic is disrupted on these ports for the duration of the inconsistency.
Reference: http://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5000/sw/operations/n5k_vpc_ops.html (graceful consistency check)
