Functions of OSI and TCP/IP Layers Q.28
| Prefix | Output Interface Identifier |
| 131.16.0.0 / 12 | 3 |
| 131.28.0.0 / 14 | 5 |
| 131.19.0.0 / 16 | 2 |
| 131.22.0.0 /15 | 1 |
The identifier of the output interface on which this packet will be forwarded is_______.
- Option : A
- Explanation : Given address 131.23. 151.76. coming to the first field of given routing table
⟹ 131.16. 0.0/12
131.0001 0111.151.76
131.0001 0000.0.0 ( given mask bits = 12)
⟹ 131.16.0.0 Matched
Coming to the 2nd field of given Routing table
⟹ 131.28.0.0/14
131.0001 0111. 151. 76
131.0001 0100.0.0 ( given mask bits = 14)
⟹ 131.20.0.0 not matched
Coming to the 3rd field of given Routing table
Error ! Not a valid link 131.19.0.0/16
131.0001 0111.151.76
131.0001 0111.0.0 ( given mask bits = 16)
⟹ 131.23.0.0 Not matched
Coming to the 4th field of given Routing table
⟹ 131.22.0.0/15
131.0001 0111.151.76
131.0001 0110.0.0 ( given mask bits = 15)
⟹ 131.22.0.0 Matched
We are getting 1st and 4th entries are matched so among them we have to picked up the longest mask bit, so output interface identifier is 1.
You must be logged in to post a comment.
You must be logged in to post a comment.