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Define Routing.
Routing is the act of finding a path to a destination and moving information accross an internetwork from the source to the destination.
What are the two key functions that a router performs?
Path determination (routing) and packet forwarding (switching). The routing function is responsible for learning and awareness. The switching function moves packets from inbound interface to outbound interface.
How does a router determine the path a packet should take to reach its destination?
Best path is determined by one of the following:

Static Routing
Dynamic Routing
Default Routing
What is the differance between a routed and a routing protocol.
A routed protocol provides the information in it's network layer to allow a packet to direct traffic and defines the use of fields within a packet. (IP, IPX, DecNet).  A routing protocol finds routes in an internetwork, exchanges routing tables, and maintaines route awareness. Routing protocols determine how routed protocols are routed. (RIP, EIGRP, OSPF, BGP)
What six types of information are stored in routing tables?
Destination network address

Next-hop address

Exiting interface


Administrative Distance

Routing Protocol Used
How do routing protocols maintain their routing tables with each other?
By transmitting routing update messages.
What is administrative distance?
AD is an interger from 0 to 255 that rates the trustworthiness of the source of the IP routing information.
What is the AD for each of the following?

Directly connected
Static route
External IGRP
Directly connected 0
Static Route         1
EIGRP                90
IGRP                 100
OSPF                110
IS-IS                115
RIP                   120
External EIGRP  170
Unknown          255
What are the four types of routes found in a routing table?
Directly connected



What is an autonomous system (AS)?
An AS is a collection of networks under common administrative control that share a common routing strategy.
What is the differance between IGP and EGP ?
IGPs route data within an AS. EGPs route data between AS's.


What is a routing metric?
A factor that determines desirability of a route. 
What are the most common routing metrics used in routing algorithms?
Hop Count
How do distance vector routing protocols function?
Also know as Bellman_Ford algorithms, distance vector routing protocols pass complete routing tables to neighbor routers. Neighbor routers combine the received routing table with their own routing tables. Each router receives a routing table from its directly connected neighbor.
How do distance vector routing protocols keep track of changes to the internetwork?
Distance vector routing protocols keep track of changes to the internetwork by periodically broadcasting updates out all active interfaces. These broadcasts contain the entire routing table. Often called "routing by rumor."
Slow convergence of distance vector routing protocols can cause inconsistant routing tables and routing loops. What are some mechanisms that distance vector protocols implement to prevent routing loops and inconsistant routing tables?
Some mechanisims that distance vector protocols implement to prevent routing loops and inconsistant routing tables are as follows:

Maximum hop count (count to infinity)

Split Horizon

Route Poisoning

Hold-down timers
What are link-state protocols? List two common link-state protocols.
They were designed to overcome the limitations of distance vector protocols. Link-state protocols respond quickly to network changes and send both triggered updates and periodic updates. 

Link-state protocols create a picture of the internetwork by determining the status of each interface (link) in the internetwork. When the interface goes down, link -state protocols send updates out all interfaces, informing routers of the downed link.

OSPF and IS-IS are the most common link-state protocols used.
Which of the following is a hybrid routing protocol?
RIP v2

EIGRP was developed by Cisco and is considered a hybrid routing protocol because it combines the aspects of distance vector with link-state protocols.
Which of the following are link-state protocols?
IS-IS and OSPF are link-state protocols.
What type of protocol is BGP?
BGP is considered an exterior gateway protocol (EGP). BGP is a routing protocol that routes routing protocols' domains (autonomous systems).
How do you configure the default route on a cisco router?
To configure a default route on a Cisco router, enter the following global command:

ip route
Convert binary number 01100100 to decimal.
This is 100 in decimal.
Convert the binary number  0101011011000010 to hexidecimal.
break binary number into groups of four starting from right to left.
0101 0110 1100 0010

Next convert to hex digits
0101 5 in hex
0110 6 in hex
1100 C in hex
0010 2 in hex

Giving you 0x56c2 in hex.
What is the range of binary values for the first octet in class B addresses?
The first octect for a class B IP address is 128 - 191 in decimal which is 10000000 - 1011111 in binary.
How many usable IP addresses are provided in a Class C network address?
254. The default subnet mask for  class c address is /24. Meaning 24 bits are used for the network number and 8 bits are reserved for hosts.
As a network administrator, you have a class B address. Assuming that the IP subnet zero command is enabled on the router, what subnet mask allow you to have 100 subnetworks with at least 500 usable hosts? 
The subnet mask is This leaves 7 bits for the networks and 9 bits for hosts.
What is the differance between static and dynamic routes?
Static routes are manually entered by the administrator.

Dynamic routes are learned automatically
How do you configure a static route on a Cisco router?
To configure a static route on a Cisco router, enter the ip route destination-network
What is a default route?
Also know as gateway of last resort, a default route is a special type of static route with an all-0s network and network mask.
Convert the decimal number 167 to binary.
What is the correct network address for host

If IP subnet zero is enabled the following subnets exist.
How many usable subnets and usable hosts do yo have if you subnet the network address with the subnet mask
14 nets with 14 hosts each
Your internet service providor has given you the IP network address of You have 18 networks, each with 1200 hosts. You want to assign one IP range per subnet, leaving room for future growth. Assuming that the IP subnet zero command is enabled on all routers, wha subnet mask would best acheive your goals? would be the best subnet mask to use to acheive your goals.
x of y cards