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 networks connected to R1.
B is incorrect answer.correct one must be A.(according to my web searchs).I think reason is , there is no information about R2 that has any ospf configuration….please correct me if i am wrong…
The only thing here is wrong is the default route.
It should be a serial 0/1 exit interface not 0/0.
This question sucks on so many levels.
We have no idea if R2 has OSPF configured or not, so A is ambiguous.
I think B is also fairly ambiguous.
The LSA’s will not have any information on the 200.0.0.0/30 network (connection to ISP) since OSPF wasn’t configured to route for this network. It does have the “default-information originate” command, but the default network is configured incorrectly. So in this sense, does “full routing table” mean R1’s full routing table? Because obviously it won’t be, since the ISP connection won’t be there.
Moreover, since when to link-state routing protocols exchange “full routing tables”? So B’s definitely misleading if that’s the right answer.
C is a really hard, too; will OSPF advertise to a neighbor how to get to that neighbor’s network? I think so; I think OSPF has analogous features to feasible successor routes and FD’s in EIGRP. But does a CCNA really need to know OSPF in this detail?
Lastly, D is dumb; I think we can rule this one out. Obviously R2 has a route for the directly connected serial route. All directly connected networks show up in the routing table, always.
If I got a question like this on a $300 test, I’d be pretty pissed off.
OK, asked a more expert friend for help.
No, OSPF does not calculate backup routes like EIGRP does.
Still, does anybody know if a router would advertise to its DR the link between it and its DR? Seems fairly redundant. This is relevant to answer C.
Yes it would. CBT nuggets says it’ll advertise every intefrace which fits a network wildcard. But link-state is not a route. So actually “default route” would not be advertised. AFAIK. So answer C looks pretty much like a good choice.
Man…you’ve got the wrong answers! Below are the choices for this question.
A – Any packet destined for a network that is not directly connected to router R2 will be dropped immediately
B – Any packet destined for a network that is not directly connected to router R1 will be dropped
C – Any packet destined for a network that is not directly connected to router R2 will be dropped immediately because of the lack of a gateway on R1
D – The network directly connected to a router R2 will not be able to communicate with the 172.16.100.0, 172.16.100.28 and 172.16.100.64 subnetworks.
E – Any packet destined for a network that is not referenced in the routing table of router R2 will be directed to R1. R1 will then send that packet back to R2 and a routing loop will occur
E is the right answer
R1 and R2 are in the same OSPF area and will share routing information. Because the default-information originate command has been issued it will (even though it’s incorrect and should be S0/1) send that information to R2. So B is the best answer available. Try not to overthink it. Cisco asks these kinds of questions all the time. They give you flawed information and ask you to make the best choice with that information.
Assume that all of the router interfaces are operational and configured correctly.
So R1 will share routing table with R2 in the same area.
How will router R2 be affected by the configuration of R1 that is shown in the exhibit?
It will receive the default route as well as the routing table even thought the default route is incorrect.
Thanks Chris. I tested it in packet tracer and B is correct.
As for me answer C sounds stupid but actually is pretty good. OSPF updates will work it says. @Default route would not be transferred” is OK too because OSPF transfers no routing information.
The answer is B – The Network Statements on R1 are correct for forming a neighbor relationship so “assume that all router interfaces are configured correctly” and assume that R2 is correctly configured with an IP on the same subnet as S0/0 on R1. OSPF will broadcast the LSA across the Serial Link and R2 will respond and form a neighbor relationship. As the Default-Information Originate statement is included in R1 it will provide that information to R2.
Yes this will cause a routing loop but that is not what the question is asking.
I am changing my answer on this:
B is wrong = OSPF does not send full routing tables.
C is wrong = the default route would be sent due to the default-information originate command.
D is wrong = you always have a route for the directly connected networks.
So the correct answer is A – the routers will not form a relationship. I guess we cannot assume that R2 has OSPF configured.
Assume that all of the router interfaces are operational and configured correctly.
B is correct
Correct answer is
It WILL form a relationship so answer A is out. OSPF does not send full routing tables (that is RIP) so answer B is out.
I think answer E is missing from your question sheet. I think this happened years ago and has been copied and copied over the years.
E – Any packet destined for a network that is not referenced in the routing table of router R2 will be directed to R1. R1 will then send that packet back to R2 and a routing loop will occur