OSPF Questions 2

Question 1

Explanation

In IPv6, you can configure many address prefixes on an interface. In OSPFv3, all address prefixes on an interface are included by default. You cannot select some address prefixes to be imported into OSPFv3; either all address prefixes on an interface are imported, or no address prefixes on an interface are imported.

Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_ospf/configuration/15-sy/iro-15-sy-book/ip6-route-ospfv3.html

Question 3

Question 4

Explanation

Because the destination of 172.16.1.1 is not present in the routing table so this router would use the default route (O*E2) to forward this packet. Usually the O*E2 is the result of the “default-information originate” command on the upstream router.

Question 5

Question 6

Explanation

Before you enable OSPF for IPv6 on an interface, you must perform the following:

+ Complete the OSPF network strategy and planning for your IPv6 network. For example, you must decide whether multiple areas are required.
+ Enable IPv6 unicast routing.
+ Enable IPv6 on the interface.

Reference: https://www.cisco.com/c/en/us/support/docs/ip/ip-version-6-ipv6/112100-ospfv3-config-guide.html

Note: If we have already had an active interface, we don’t need to configure the router ID for OSPFv3 anymore because the device will automatically choose that IPv4 address for its router ID).

Question 7

Question 8

Explanation

Hierarchical design of OSPF (basically means that you can separate the larger internetwork into smaller internetworks called areas) helps us create a network with all features listed above (decrease routing overhead, speed up convergence, confine network instability to single areas of the network).

Question 9

Question 10

Explanation

To form an adjacency (become neighbor), router A & B must have the same Hello interval, Dead interval and AREA number.

Question 11

Question 12