Which key element would the flow entry contain?

A network administrator is planning a flow table entry that provides fast failover for the traffic flow in case a link fails.

Which key element would the flow entry contain?
A . a group identifier that specifies at least two output ports
B . a backup set action that modifies the packet and sends it to the controller
C . a forward action to the reserved port NEAREST_ACTIVE
D . a go-to-table action that sends traffic to another table if the port is down

View Answer

Answer: A

Explanation:

The FAST-FAILOVER group is designed specifically to detect and overcome port failures.

The FAST-FAILOVER (FF) group. A FF group is designed to detect and respond to port failures. Each bucket has a watch port/group as a special parameter, which monitors the liveness of that port or group being watched. Only one bucket is used at a time, and the bucket will only be changed if the watch port/ group of the bucket transitions from up to down. Upon such an event, another bucket will be chosen whose watch port/group indicates the link is up.

References: https://floodlight.atlassian.net/wiki/display/floodlightcontroller/How+to+Work+with+Fast-Failover+OpenFlow +Groups