JN0-102: Juniper Networks Certified Associate Junos Exam - Routing Table and OSPF Configuration

Routing Table and OSPF Configuration

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Question

-- Exhibit --

user@router> show route

inet.0: 9 destinations, 9 routes (9 active, 0 holddown, 0 hidden)

+ = Active Route, - = Last Active, * = Both

10.10.10.91/32 *[Direct/0] 00:09:40

>via lo0.0

10.10.10.92/32 *[OSPF/10] 00:01:50, metric 1

>to 172.16.1.2 via ge-0/0/2.0

100.100.1.0/24 *[Static/5] 00:01:50

Reject -

172.16.1.0/24 *[Direct/0] 00:06:09

>via ge-0/0/2.0

172.16.1.1/32 *[Local/0] 00:06:09

Local via ge-0/0/2.0 -

192.168.0.0/16 *[Aggregate/130] 00:00:06

Reject -

192.168.0.0/17 *[Aggregate/130] 00:00:06

>to 172.16.1.2 via ge-0/0/2.0

192.168.50.0/24 *[Static/5] 00:00:06

>to 172.16.1.2 via ge-0/0/2.0

192.168.51.0/24 *[Static/5] 00:00:06

>to 172.16.1.2 via ge-0/0/2.0

user@router> show configuration policy-options

policy-statement demo {

term 1 {

from {

route-filter 192.168.0.0/16 longer accept;

}

then reject;

}

}

user@router> show configuration protocols ospf

export demo;

area 0.0.0.0 {

interface ge-0/0/2.0;

}

-- Exhibit --

Given the configuration and routing table shown in the exhibit, which routes will be advertised to OSPF neighbors because of the demo policy?

Answers

Explanations

Click on the arrows to vote for the correct answer

A. B. C. D.

D

Based on the exhibit, the router has nine routes in its routing table. Out of these nine routes, the demo policy has been configured to match routes in the 192.168.0.0/16 address space that are longer than the /16 prefix length, and reject them.

The OSPF protocol has also been configured to export the routes that match the demo policy. Therefore, only routes that are not rejected by the demo policy will be advertised to OSPF neighbors.

Let's go through each of the routes in the routing table to determine which ones will be advertised to OSPF neighbors:

  • 10.10.10.91/32: This route is a directly connected route and will not be advertised to OSPF neighbors.
  • 10.10.10.92/32: This route is learned via OSPF and will be advertised to OSPF neighbors.
  • 100.100.1.0/24: This route is a static route and will not be advertised to OSPF neighbors because it does not match the demo policy.
  • 172.16.1.0/24: This route is a directly connected route and will not be advertised to OSPF neighbors.
  • 172.16.1.1/32: This route is a local route and will not be advertised to OSPF neighbors.
  • 192.168.0.0/16: This route is an aggregate route and will not be advertised to OSPF neighbors because it matches the demo policy and is rejected.
  • 192.168.0.0/17: This route is an aggregate route and will not be advertised to OSPF neighbors because it matches the demo policy and is rejected.
  • 192.168.50.0/24: This route is a static route and will be advertised to OSPF neighbors because it does not match the demo policy.
  • 192.168.51.0/24: This route is a static route and will be advertised to OSPF neighbors because it does not match the demo policy.

Therefore, the correct answer is option C: 192.168.50.0/24 and 192.168.51.0/24 will be advertised to OSPF neighbors because they do not match the demo policy, while 192.168.0.0/16 and 192.168.0.0/17 will not be advertised because they match the demo policy and are rejected.