JUNOS Enterprise Routing

Chapter Review Answers

1. Answer: A. The default next hop type for an aggregate route is reject, which when matched does result in the M7i’s system board having to create an ICMP error. Even with rate-limiting safeguards, these messages consume system processing, but not forwarding resources.

2. Answer: C. A floating static needs to have a preference that is less preferred than the route it backs up. OSPF externals have a preference of 150, so you need a value that is higher; otherwise, the static route will take precedence over the OSPF route.

3. Answer: D. The loops argument to the autonomous-system statement affects received route updates only. Further, whatever value is specified, subtract one for the number of local AS instances that are permitted. The default setting of 1 will reject any route with 1 instance of the local AS number.

4. Answer: A. Point-to-point interfaces can contribute to a generated route because an explicit next hop is not required. LAN interfaces require some route—either static or learned—to activate an aggregate or generated route. Policy is used to exclude routes from contributing, not to include.

5. Answer: D. All of the commands listed will display the Layer 3 VPN instance route table. Some are simply more verbose or more direct by displaying only the table desired.

6. Answer: B. The default RIP import policy accepts RIP routes. To send direct routes, you need the direct protocol, and to readvertise RIP learned routes, you need the RIP protocol. The default RIP export ...