Chapter 4-5 - Part3

Question 1

What is a forwarding table / flow table?

Answer 1

“match plus action” abstraction.

Match: pattern values

Actions: drop, forward, modify, etc.

Question 2

Difference between per router vs SDN control plane?

Answer 2

Per-router: individual algo components in every router interact together to make forwarding tables.

SDN: remote controller computes and installs forwarding tables in routers so routers dont interact with one another

Question 3

Advantage of SDN?

Answer 3

Centralized control plane

1. easier network management
2. avoid misconfigurations
3. flexibility

Question 4

Structure of SDN?

Answer 4

DATA PLANE:
- Switches/routers

CONTROL PLANE:
- SDN Controller with northbound/southbound API
- Network control apps: routing, load balance, etc

Question 5

What is the OpenFlow protocol? 2 main classes?

Answer 5

Operates between the controller and the switches

Uses TCP

2 main classes:
- Controller-to-switch
- Switch-to-controller

Question 6

Some controller-to-switch messages?

Answer 6

1. configure
2. modify-state
3. packet-out

Question 7

Some switch-to-controller messages?

Answer 7

1.packet-in

2. flow-removed
3. port status