RIP Questions

Note: If you are not sure about RIP, please read our RIP Tutorial.

Question 1

Explanation

“Enable RIP” is surely correct to configure RIPv2 but “enable auto-summary” is not recommended. Maybe there is another suitable option for this question (like “use ‘version 2’ command” or “Allowing Unicast Updates for RIP”).

Question 2

Explanation

To enable RIP surely we have to enable it first (with the “router rip” command in global configuration mode) -> E is correct.

RIPv2 sends its updates via multicast but in Nonbroadcast Multiple Access (NBMA) environment, multicast is not allowed so we have to use unicast to send RIPv2 updates -> D is correct.

Question 3

Explanation

The split-horizon rule states that “a router never sends information about a route back in same direction which is original information came”. This rule is used in distance vector protocol (like RIP or EIGRP) to prevent Layer 3 routing loop.

Question 4

Explanation

A passive-interface with RIP prevents that interface from sending RIP advertisements but it is still receiving RIP updates from other RIP neighbors. This behavior is different from EIGRP and OSPF where the passive-interface statement stops forming neighbor adjacencies over that link.

Question 5

Explanation

Distance vector protocols (like RIP) exchanges the entire routing information each time the routers send the updates.

Note: EIGRP is considered an advanced distance vector protocol so it does not send the whole routing table for each update.

Question 6

Explanation

The difference between RIPv1 and RIPv2 is RIPv1 is a classful protocol (no support for VLSM or CIDR) while RIPv2 is a classless protocol (which supports VLSM and CIDR). Therefore in this question if we forget to enable RIPv2 then the router will use RIPv1 and it only advertise major network 172.16.0.0/16 to other routers. By enabling RIPv2 (via the “version 2” command) the router will advertise two subnets 172.16.10.0/27 & 172.16.10.32/28.

Question 7

Question 8

Explanation

Use the ip rip v2-broadcast command to broadcast RIP Version 2 broadcast updates to hosts that do not listen to multicast broadcasts. Version 2 updates (requests and responses) will be sent to the IP broadcast address 255.255.255.255 instead of the IP multicast address 244.0.0.9. For example:

Router(config)# interface ethernet3/1
Router(config-if)# ip address 172.1.1.1 255.255.255.0
Router(config-if)# ip rip v2-broadcast

Reference: https://www.cisco.com/c/en/us/td/docs/ios/12_2/iproute/command/reference/fiprrp_r/1rfrip.html

Question 9

Explanation

RIPv2 sends its updates via multicast. Use the ip rip v2-broadcast command to broadcast RIP Version 2 updates to hosts that do not listen to multicast broadcasts. Version 2 updates (requests and responses) will be sent to the IP broadcast address 255.255.255.255 instead of the IP multicast address 224.0.0.9.

Reference: https://www.cisco.com/c/en/us/td/docs/ios/iproute_rip/command/reference/irr_book/irr_rip.html

Question 10