Exam 300-320 topic 1 question 18 discussion

Question asks for "blocking". Answer is STP.

- VPC is loop free - VPC Does Not block ports, VPC Eliminates Spanning Tree Protocol (STP) blocked ports - STP is who block ports https://www.ciscolive.com/c/dam/r/ciscolive/emea/docs/2016/pdf/BRKDCT-2378.pdf Cisco Live Berlin, Page 99 vPC Benefits: No Blocked Ports. VPC Provides a loop-free topology: https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/7-x/interfaces/configuration/guide/b_Cisco_Nexus_9000_Series_NX-OS_Interfaces_Configuration_Guide_7x/b_Cisco_Nexus_9000_Series_NX-OS_Interfaces_Configuration_Guide_7x_chapter_01000.html https://www.cisco.com/c/dam/en/us/td/docs/switches/datacenter/sw/design/vpc_design/vpc_best_practices_design_guide.pdf

The main hint in that question is "Which technology can block interface". vPC is not blocking any interface but it's rather using all interfaces/links. Only STP will block one of interface to remove loop from broadcast domain.

As per cisco (https://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/Campus/HA_campus_DG/hacampusdg.html): Highly available networks require redundant paths to ensure connectivity in the event of a node or link failure. Various versions of Spanning Tree Protocol (STP) are used in environments that include redundant L2 loops. STP lets the network deterministically block interfaces and provide a loop-free topology in a network with redundant links.

vPC. Designing Cisco Network Service Architectures (ARCH): Foundation Learning Guide Chapter 5 page no#243