200-301 Question 269
Single answerYou are troubleshooting a network issue on a router running multiple routing protocols. When analyzing the routing table, you notice that some routes are marked with the code 'O', while others are marked with the code 'E2'. What do these routing protocol codes indicate about the origin of the routes?
- A
'O' represents routes learned via OSPF, and 'E2' represents OSPF external routes with a fixed metric.
- B
'O' represents routes learned via OSPF, and 'E2' represents EIGRP external routes with a fixed metric.
- C
'O' represents routes learned via OSPF, and 'E2' represents static routes redistributed into OSPF.
- D
'O' represents routes learned via OSPF, and 'E2' represents RIP routes redistributed into OSPF.
Show answer and explanation
Correct answer: A
Explanation
Routing protocol codes in a routing table provide insight into how a route was learned. 'O' indicates that the route was learned via OSPF, an interior gateway protocol. 'E2' is specific to OSPF and represents external routes (routes redistributed into OSPF from another routing domain) with a Type 2 metric, meaning the cost is fixed regardless of the number of hops. Understanding these codes is essential for diagnosing and troubleshooting routing behavior in a network.
- A. Correct.
'O' represents routes learned via OSPF, and 'E2' represents OSPF external routes with a fixed metric. This is correct because 'O' is the code for OSPF, and 'E2' indicates OSPF external routes with a Type 2 metric which does not increase along the path.
- B. Incorrect.
'O' represents routes learned via OSPF, and 'E2' represents EIGRP external routes with a fixed metric. This is incorrect because 'E2' is specific to OSPF external routes, not EIGRP.
- C. Incorrect.
'O' represents routes learned via OSPF, and 'E2' represents static routes redistributed into OSPF. This is incorrect because while static routes can be redistributed into OSPF as external routes, 'E2' indicates the metric type, not the source of the route.
- D. Incorrect.
'O' represents routes learned via OSPF, and 'E2' represents RIP routes redistributed into OSPF. This is incorrect because 'E2' refers to the metric type of OSPF external routes, not specifically to RIP routes.