IPv4 Routing

Question 1

For a router to route.. the router must know (list 3 things!)

Answer 1

Destination IP address (from packet header), neighbour routers, possible routes to the target network, best route to the target network, how to maintain and verify routing information

Question 2

How can a router learn about networks?

Answer 2

From a network directly connected to the router, statically from admin, dynamically from neighbour routers

Question 3

What is the route of last resort?

Answer 3

Default routing. It does not define a specific target network. Used by a router to forward traffic when no specific route to target network. 0.0.0.0 0.0.0.0

Question 4

Describe dynamic routing

Answer 4

Router learns possible routes to remote networks from neighbors. If multiple possible routes to same network exist, lowest admin distance determines best route

Question 5

What is distance vector routing protocol?

Answer 5

A type of dynamic routing protocol. Distance is based on number of ‘hops’. Less hops = best. Vector - direction. Example: RIP

Question 6

What is link state routing protocol?

Answer 6

A type of dynamic routing protocol. Neighbour routers understand state of link between them. State of accumulated links determines admin distance (AD). Lowest AD determines best route. Example: OSPF.

Question 7

What are hybrid routing protocols?

Answer 7

A type of dynamic routing protocol. Uses elements of both distance vector and link state. Example: EIGRP

Question 8

List the default admin distances:

Answer 8

Here, have a chart! :)

Question 9

What is EIGRP?

Answer 9

Enhanced Interior Gateway Routing Protocol

Question 10

Which of the following is called an advanced distance-vector routing protocol?
A. OSPF

B. EIGRP

C. BGP

D. RIP

Answer 10

B. EIGRP

Question 11

When a packet is routed across a network, the ____________ in the packet changes at every hop while the _________ does not.

Answer 11

MAC address, IP address.

Since the destination MAC address is different at each hop, it must keep changing. The IP address, which is used for the routing process, does not.

Question 12

Which of the following is NOT an advantage of static routing?

A. Less overhead on the router CPU

B. No bandwidth usage between routers

C. Adds security

D. Recovers automatically from lost routes

Answer 12

D. Recovery from a lost route requires manual intervention by a human to replace the lost route.

Question 13

True/False: To reach a remote host you must know the MAC address of the remote host

Answer 13

Fale. The MAC address would be the local router interface, not the remote host

Question 14

What command do you use to view the ARP cache on your host?

Answer 14

arp -a