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ICND1 – IP Routing 4

June 14th, 2017 in ICND1 100-105 Go to comments

Note: The ICND1 exam requires candidates to understand basic knowledge of dynamic routing protocols (RIP, EIGRP, OSPF).

Question 1

Question 2

Question 3

Explanation

A and E are correct according to the theory of RIP.

RIP version 1 updates are broadcasts, and RIP version 2 updates are multicast to 224.0.0.9 -> B is not correct.

RIP v1 is a classful routing protocol but RIP v2 is a classless routing protocol -> C is correct.

RIPv1 and RIPv2 have the same default administrative distance of 120 -> D is not correct.

RIPv2 is a classless routing protocol so it does send the subnet mask in updates -> F is not correct.

Question 4

Explanation

Host1 can ping the Serial interface of R2 because R1 has the network of 192.168.1.4/30 as directly connected route. But R1 does not know how to route to the network of Host2 (192.168.1.128/26) so R1 will drop that ping without trying to send it out S0/0 interface. To make the ping work, we have to configure a route pointing to that network (for example: ip route 192.168.1.128 255.255.255.192 s0/0 on R1).

Question 5

Explanation

The route 192.168.5.0/24 currently has the metric of 15 so this router will add 1 hop count before sending out to its neighboring router. With RIP, a metric of 16 means that network is down -> it will not be installed in the routing table of the neighboring router.

Question 6

Question 7

Explanation

The passive interface only prevents routing updates from being sent and received on that interface. It does not affect the default route. But if we configure a default route like this:

Router(config)#ip route 0.0.0.0 0.0.0.0 192.168.1.2

Then if the next-hop address is down (unreachable) then this default route would be removed from the routing table.

Question 8

Question 9

Comments (1) Comments
  1. Anonymous
    August 18th, 2017

    There is a question in http://www.9tut.net/final_flash/ICND1v3/All_Questions_3/quiz.html
    (Question 11)
    Which information is used to install the best route to a destination in IP routing table?
    a: the Predix Length
    b: the interface number
    c: the autonomous system
    d: the tunnel ID.
    ————————————-
    the correct answer from the quiz is a: the prefix length.

    however, my understanding is: prefix length decided the network mask, like /24 is the 255.255.255.0.

    why not the answer b? my understanding is:
    after configured, each interface has its IP address. the router will know which interface to send out the packet.

    Thanks