JN0-102 · Question #33
How does the PFE handle unicast transit traffic destined for an existing forwarding table entry?
The correct answer is A. It sends the traffic through one egress port toward its destination. The Packet Forwarding Engine (PFE) handles unicast transit traffic by performing a lookup in the forwarding table and sending it out a single egress port towards its destination.
Question
How does the PFE handle unicast transit traffic destined for an existing forwarding table entry?
Options
- AIt sends the traffic through one egress port toward its destination.
- BIt sends the traffic through multiple egress ports to all available receivers.
- CIt sends the traffic through an internal link to the RE.
- DIt sends the traffic to the local system for further processing.
How the community answered
(23 responses)- A91% (21)
- C4% (1)
- D4% (1)
Why each option
The Packet Forwarding Engine (PFE) handles unicast transit traffic by performing a lookup in the forwarding table and sending it out a single egress port towards its destination.
For unicast transit traffic, the PFE performs a lookup in the forwarding table and directs the packet to a single best-path egress interface towards its destination.
Sending traffic through multiple egress ports is characteristic of broadcast or multicast traffic, not standard unicast forwarding.
Sending transit traffic to the Routing Engine (RE) would severely impact performance, as the RE handles control plane and exception traffic, not high-volume forwarding.
Sending traffic to the local system for further processing implies the traffic is destined for the device itself (exception traffic), not passing through it as transit traffic.
Concept tested: PFE unicast transit traffic forwarding
Source: https://www.juniper.net/documentation/us/en/software/junos/junos-os-fundamentals/topics/topic-map/junos-os-fundamentals-architecture.html
Topics
Community Discussion
No community discussion yet for this question.