P4 Flashcards
Why were switches itself originally not programmable (in SDNs)?
In the past, programable switches were very slow. The speed difference in the modern age is now very small.
How high is the visibility of events at the data plane in SDNs?
Low
How high is the visibility of events at the data plane in P4?
high
Is P4 runtime reprogrammable?
yes
What are the advantages of a programmable DP?
- Flexible data plane (DP)
– Optimizable to specific network
– Quick updates - Hardware independent
- Potentially more robust
– Only add the features you need - Improved telemetry
What are the disadvantages of programmable DP?
- Robustness/security
– Introduce own bugs/security flaws in data plane - More responsibilities for network operator
Which component in P4 is responsible for QoS and telemetry?
Egress controller
When is the checksum verified in P4?
After the parser
In P4, which component populates the match tables?
The controller
In P4, Which component defines the possible actions?
ingress & egress
Can counters be read from the data plane?
No, only the control plane