Can somebody explain me this Options

[mehnihma]

Hello all.

I thinks answer answer is B

And can anybody explain me this?

Thanks

[humbertoronto]

the answer is A because

in the picture you see
.....
router ospf 1

.....that is the configuration that according to the question belong to R1

so this command tell us what is the AS. (autonomus system) the area...

and in the picture R2 belong to ospf area 0

see you, good luck

[mehnihma]

the answer is A because

in the picture you see
.....
router ospf 1

.....that is the configuration that according to the question belong to R1

so this command tell us what is the AS. (autonomus system) the area...

and in the picture R2 belong to ospf area 0

see you, good luck

autonomus system is for EIGRP
and router ospf 1 is for procces ID if I'm not wrong and that doesn't have anything with neigbours .
There are is network x.x.x.x .x.x.x.x area 0 so all routers are in the same area.

And still don't get how answer A is correct, or is ti?

[humbertoronto]

autonomus system is for EIGRP
and router ospf 1 is for procces ID if I'm not wrong and that doesn't have anything with neigbours .
There are is network x.x.x.x .x.x.x.x area 0 so all routers are in the same area.

And still don't get how answer A is correct, or is ti?

ok brother, sorry for use the wrong word you are right the ID ( according to self study guide )is different, now change AS for Id.

the correct answer A.
:-)
Please look the picture appear number Id different when show the route... for that reason are in different area.

router ospf 1
.......
more routes ..
if they belong to the same area

should appear
router ospf 0
more .....routes.



see you .
if you still persist simulate the scenario.
to get that show you will have to put the router in different area then you will have the same.

[ankitc]

To become OSPF neighbors:

1. Subnet mask used.

2. Subnet address ( as derived using the subnet mask and each router's interface IP address)

3. Hello Interval and Dead Interval

4. OSPF area ID

5. Authentication ( optional )

If any of these differ, Routers cannot become OSPF neighbors.
In our case, the subnets and subnet masks are different.

[wildbill]

ok brother, sorry for use the wrong word you are right the ID ( according to self study guide )is different, now change AS for Id.

the correct answer A.
:-)
Please look the picture appear number Id different when show the route... for that reason are in different area.

router ospf 1
.......
more routes ..
if they belong to the same area

should appear
router ospf 0
more .....routes.



see you .
if you still persist simulate the scenario.
to get that show you will have to put the router in different area then you will have the same.

The idea of doing router ospf 0 is crazy. You are only allowed to define process-id's of 1-65535. THIS IS NOT AN AUTONOMOUS SYSTEM NUMBER. That means they don't have to match.

The number at the end of the router ospf statement is just a process-id and does not have to be the same on all routers. It only defines the process on that router so it can keep that ospf calculation separate from other processes. Answer B is correct for the following reasons :

1.The area ID defined at the end of the first network statement is correct.... it is area 0.
2. The interfaces of each router are in the same network (the question begins by saying assume all interfaces on R2 are configured correctly).
3. The question does NOT say anything about a password or hello and dead timers.
4. The configuration does not show R1 being configured for a passive interface on the link to R2, nor does it show a route map/ ACL denying those routes be sent.
5. I am a CCNP and have been using OSPF for a LONG time and have never heard of a "Regional Identifier" or a "Distal Region" to be marked

The test prep site you got that from has the answer wrong. The only way those two routers will not form a relationship with the given information is if the timers are set wrong or authentication is configured correctly. That is the only way it will fail, and since the question states "assume all routers are configured correctly" I don't think that is the case.

On a side note. The last comment states that the router's interfaces are on different networks. That is not correct because the question says they are not. Going back to "assume all routers are configured correctly" they CAN'T be on different subnets. The first network statement includes the R2's interface in the 0.0.0.3 wildcard mask. Everything checks out so you are correct that the answer is B and the test prep people are wrong.

Bill

[Renny]

The idea of doing router ospf 0 is crazy. You are only allowed to define process-id's of 1-65535. THIS IS NOT AN AUTONOMOUS SYSTEM NUMBER. That means they don't have to match.

The number at the end of the router ospf statement is just a process-id and does not have to be the same on all routers. It only defines the process on that router so it can keep that ospf calculation separate from other processes. Answer B is correct for the following reasons :

1.The area ID defined at the end of the first network statement is correct.... it is area 0.
2. The interfaces of each router are in the same network (the question begins by saying assume all interfaces on R2 are configured correctly).
3. The question does NOT say anything about a password or hello and dead timers.
4. The configuration does not show R1 being configured for a passive interface on the link to R2, nor does it show a route map/ ACL denying those routes be sent.
5. I am a CCNP and have been using OSPF for a LONG time and have never heard of a "Regional Identifier" or a "Distal Region" to be marked

The test prep site you got that from has the answer wrong. The only way those two routers will not form a relationship with the given information is if the timers are set wrong or authentication is configured correctly. That is the only way it will fail, and since the question states "assume all routers are configured correctly" I don't think that is the case.

On a side note. The last comment states that the router's interfaces are on different networks. That is not correct because the question says they are not. Going back to "assume all routers are configured correctly" they CAN'T be on different subnets. The first network statement includes the R2's interface in the 0.0.0.3 wildcard mask. Everything checks out so you are correct that the answer is B and the test prep people are wrong.

Bill

[Renny]

I agree with you Bill-

OSPF 1 is a process identifier and is only significant local to the router.
So I think the answer of test is wrong... I don't see any reason for no to from adiacency between the routers.

Bye.

Renny

[Renny]

The process ID can be any positive integer 1-65535

Bye

Renny