Refer to the exhibit.
Assume that all of the router interfaces are operational and configured correctly. How will router R2
be affected by the configuration of R1 that is shown in the exhibit?
A.
Router R2 will not form a neighbor relationship with R1.
B.
Router R2 will obtain a full routing table, including a default route, from R1.
C.
R2 will obtain OSPF updates from R1, but will not obtain a default route from R1.
D.
R2 will not have a route for the directly connected serial network, but all other directly connected
networks will be present, as well as the two Ethernet networks connected to R1.
Explanation:
Open Shortest Path First
http://en.wikipedia.org/wiki/Open_Shortest_Path_First
The configuration of R1 shows “router ospf 1” however, the diagram also shows that both routers
should be in the backbone OSPF Area of “0”. When routers are in different OSPF areas they will not
form a neighbor relationship. Neighbor relationships As a link state routing protocol, OSPF
establishes and maintains neighbor relationships in order to exchange routing updates with other
routers. The neighbor relationship table is called an adjacency database in OSPF. Provided that OSPF
is configured correctly, OSPF forms neighbor relationships only with the routers directly connected
to it. In order to form a neighbor relationship between two routers, the interfaces used to form the
relationship must be in the same area. Generally an interface is only configured in a single area,
however you can configure an interface to belong to multiple areas. In the second area, such an
interface must be configured as a secondary interface. (A neighbor state simulation shows how
neighbor state changes from Down to Full Adjacency progressively with exchanging Hello, DD,
Request, Update, and Ack packets).
I believe this question has the wrong answer. All of these networks are being advertised as being in Area 0. Router ospf “1” is the process ID for this instance of OSPF.
This is wrong OSPF Process ID’s don’t need to match!
http://www.ciscopress.com/articles/article.asp?p=2294214
Snippet from this “To enable the OSPF process on the router, use the router ospf process-id command. Process ID numbers between neighbors do not need to match for the routers to establish an OSPF adjacency. The OSPF process number ID is an internally used identification parameter for an OSPF routing process and only has local significance. However, it is good practice to make the process ID number the same on all routers. If necessary, you can specify multiple OSPF routing processes on a router, but you need to know the implications of doing so.”
I think the guy who wrote the explanation is confusing eigrp AS with ospf area and thrown process id’s in the mix as well, bad and factually incorrect explanation. answer is B
The answer is correct, it is A. The process id command is a different command used elsewhere in the configuration.
Disregard my previous statement.
The correct answer is B – Process ID’s do not need to be the same with OSPF hence the reason the area needs to be specified when configuring the networks.
Réponse B: http://www.aiotestking.com/cisco/how-will-router-r2-be-affected-by-the-configuration-of-r1-that-is-shown-in-the-exhibit/
Answer is A. R2 doesn’t have an IP on the serial link to R1, so cannot exchange routing information.
Assume that all of the router interfaces are operational and configured correctly.
Answer is A. Default Router is pointed incorrectly towards S0/0 so a routing loop will occur and a neighbor relationship will not form.
You are correct regarding routing loop -> it will occur due to static route on R1. But this fact in no way affects OSPF neighbor process, so neighborship will form!
-> This situation in fact is why static routes are not recommended in combination with routing protocols – loops can occur.
-> Correct answer is “B”.
The answer is B. The 2 routers will join as neighbors and router 2 will show the default route in it’s routing table: O*E2 0.0.0.0/0 [110/1]
VALID ANSWER IS “B”