Openflow Flow Tables
Consider the 4-router network shown below, where packet forwarding is controlled by flow tables (e.g., configured via OpenFlow in an SDN controller), rather than by a forwarding table computed by a routing algorithm. The addresses of networks attached to each of the router is also shown. The interfaces at each of the routers are also as indicated.
Suppose we want the following forwarding behavior of packets to be implemented:
- Packets coming from the source network attached to s2 and destined to the network attached to s3 should be forwarded along the path: s2 -> s3. Assume that at s3 that only HTTP traffic is allowed to enter the network.
Question List
1. For router s2, what should the value of the 'IP Src' be? Pick either a specific address (including CIDR), any, or none
2. For router s2, what should the value of the 'IP Dst' be? Pick either a specific address (including CIDR), any, or none
3. For router s2, what should the value of the 'Src Port' be? Pick either a specific port, or any
4. For router s2, what should the value of the 'Dst Port' be? Pick either a specific port, or any
5. For router s2, what should the value of the 'IP Proto' be? Pick either TCP, UDP, or any
6. For router s2, what should the action of the rule be? Some examples include forward, allow, deny, etc
7. For router s2, what interface should the packets be forwarded to?
8. For router s3, what should the value of the 'IP Src' be? Pick either a specific address (including CIDR), any, or none
9. For router s3, what should the value of the 'IP Dst' be? Pick either a specific address (including CIDR), any, or none
10. For router s3, what should the value of the 'Src Port' be? Pick either a specific port, or any
11. For router s3, what should the value of the 'Dst Port' be? Pick either a specific port, or any
12. For router s3, what should the value of the 'IP Proto' be? Pick either TCP, UDP, or any
13. For router s3, what should the action of the rule be? Some examples include forward, allow, deny, etc
14. For router s3, what interface should the packets be forwarded to?
Solution
(Q1-Q7) Rule 1. | IP_Src=128.120/16, IP_Dst=128.121/16, Src_Port=Any, Dst_Port=Any, IP_Protocol=Any, Action=Forward(2) |
(Q8-Q14) Rule 2. | IP_Src=128.120/16, IP_Dst=128.121/16, Src_Port=80, Dst_Port=Any, IP_Protocol=TCP, Action=Forward(1) |
That's incorrect
That's correct
The answer was: 128.120/16
The answer was: 128.121/16
The answer was: Any
The answer was: Any
The answer was: Any
The answer was: Forward
The answer was: 2
The answer was: 128.120/16
The answer was: 128.121/16
The answer was: 80
The answer was: Any
The answer was: TCP
The answer was: Forward
The answer was: 1