Final Flashcards
1
Q
Cisco routers “____” the Internetwork Operating System (IOS)
A
run
2
Q
An operating system manages the __________ and _________ associated with a computer
A
hardware
software
3
Q
The IOS is responsible for …
A
- Managing router interfaces
- Maintaining routing table
- Routing network traffic ( packets ) quickly and efficiently between network devices
- Providing security to control access to the router and stop unauthorized network use -
4
Q
To configure a Cisco router, a network administrator must first
A
locate the router’s console port
5
Q
The console port is administratively named ______ and is physically located on the back of the router
A
con 0
6
Q
The second step to configure a Cisco router is to
A
identify the serial port on the computer
7
Q
The third step to configure a Cisco router is to
A
Connect the computer to the router using console cable
8
Q
The fourth step to configure a Cisco router is to
A
configure your computer’s terminal emulation software for 9600 baud , 8 data bits , no parity, and 2 stop bits
9
Q
The fifth step to configure a Cisco router is to
A
run your computer’s terminal emulation software and open a console window into your router
10
Q
The sixth step to configure a Cisco router is to
A
Power up the router
11
Q
When power is applied a router will first run a
A
power on self test (POST)
12
Q
tests the hardware to verify that all components of the device are operational and present
A
POST
13
Q
After POST , the router …
A
- Looks for an IOS file in flash memory
- Expands the file
- Loads the Cisco IOS into RAM
14
Q
After the Cisco IOS is loaded , the router …
A
- Looks in non-volative RAM ( AM) to locate the router’s startup configuration (startup-config)
- If found, the router loads the startup-config into RAM and the router displays the Router> prompt .
- Otherwise, the router enters setup mode and displays the prompt Would you like to enter the initial configuration dialog yes/no:
15
Q
When the Cisco startup-config is loaded into RAM, the router will display the
A
Router > prompt
16
Q
If you type “___” the prompt , then the router will display the Router > prompt
A
N
17
Q
The Router> prompt represents a
A
Cisco IOS command line interface (CLI)
18
Q
A Cisco ISO CLI is referred to as an
A
EXEC session
19
Q
Two levels of EXEC sessions
A
- User EXEC
– Privileged EXEC
20
Q
Only allow access to limited of basic router monitoring commands
A
User EXEC
21
Q
Privileged EXEC allows
A
– Allows access to all router commands , including configuration and management
-Can be password protected to allow only authorized users the ability to configure and maintain the router
22
Q
is initially in User EXEC, which displays a Router > prompt
A
Router
23
Q
To enter Privileged EXEC, issue the command
A
Router>enable and press ENTER
24
Q
The Privileged EXEC prompt is
A
Router#
25
To return back to User EXEC , issue the command
Router #disable
26
To exit any and all levels, issue the "______” or "_________" commands at any prompt
exit
logout
27
To restart (reboot ) a router , issue the command
reload at the Privileged EXEC prompt
Router#reload
28
Issuing the command "?" at a CLI prompt will display
the commands available at that level
29
Issuing the command at a CLI prompt will displays
the commands that begin with the letter "co” at that level
30
```
Many Cisco IOS commands can be abbreviated
Show abbreviations for:
- show
- interface
- Ethernet
```
- sh for show
- int for interface
- eth for Ethernet
31
Issuing the command "ping? ” at the user EXEC prompt will display
the command line arguments that are required for a given command
32
A command line argument is
Carriage Return
33
If the user enters a Cisco IOS command improperly ( e.g. typo or invalid command option), then the router will
Called CLI Syntax Checking
inform the user and indicate where the error has occurred
34
Cisco IOS provides _________ to speed command line command editing
Hot Keys
35
There are three ways to connect to a router
```
Console port (con 0)
Auxiliary port (aux 0)
Virtual terminal (vty0, vty1, vty2)
```
36
You must enter global configuration mode to configure the ...
- console port ( con 0)
- auxilliary port (aux 0)
- or the virtual terminal ports (vty 0-4)
37
If you enter configure ” at the Router # prompt you will enter
global configuration mode .
38
If you enter configure X” at the Router# prompt Where X is one of the following three modes ...
- terminal
- memory
- network
39
Name the five router interfaces
Router> enable
Router#configure terminal Router(config)#exit
Router#disable
Router >
40
To configure vty line
To configure vty lines 1, 2 & 3
To configure vty line 4
Issue Cisco IOS command line vty 0 0
Issue Cisco IOS command line vty 1 3
Issue Cisco IOS command line vty 4 4
41
Often you want to provide information to users who are authorized to access your router.
Likewise , you will provide warning to those who attempt to access your router without proper authorization.
Both cases are satisfied by creating
banners
42
A _______ banner is displayed on all terminals connected via the console port, the auxiliary port, and virtual terminals
MOTD
43
How to create a MOTD banner
Router>enable
| Router#configure terminal Router(config) #banner motd *YOURMESSAGEHERE*
44
A ______ banner is displayed on all connected terminals when router requires login credentials
Login
45
How to create a login banner
Router >enable
| Router# configure terminal Router(config) #banner login * YOURMESSAGEHERE
46
Cisco routers provides five (5) different passwords
- Console
- Telnet
- Auxiliary
- Enable
- Enable Secret (Encrypted by default)
47
The _________ password is used to secure a console login. Generates a clear text password that can be seen when the show running- configuration Cisco IOS command is issued
console
48
How to create a password
Router>enable
Router#configure terminal Router( config)#line console 0
Router (config-line) #password CONSOLEPASSWORDHERE
49
To enable password checking at login, the login command in line configuration mode:
To disable password checking and allow connections without a password , use the no form of this command:
Router(config-line)#login
Router (config - line)# no login
50
Use the exec-timeout command to configure the inactive session timeout on the console port or the virtual terminal
Give example:
- Router(config.line ) #exec-timeout INTEGERHERE
| - INTEGERHERE is [0, 525600]
51
What is used for the exec-timeout command to use default
no
Router(config-line)#no exec-timeout
Or
Router(config-line)#exec-timeout 0 0
Both have the same effect
52
Generates a clear text password that can be seen when the show running-configuration Cisco IOS command is issued
Auxiliary password
53
a Generates a encrypted password that can be seen when the show running - configuration Cisco IOS command is issued
Enable secret password
54
For the purposes of routing packets, routers are equipped with one or more interfaces
These interfaces are one of the following ...
- Ethernet ( eth)
- FastEthernet (fe)
- Serial (ser)
55
Recall that each Ethernet and Serial interface represents a subnet , which is also
One broadcast domain
56
Ethernet interfaces on older routers are called
AUI ports
57
AUI/RJ45 transceivers must be used to connect
the router to a switch
58
How to configure Ethernet interface
Router>enable
Router# configure terminal Router(config)# interface ethernet NUMBER
Router(config-if)#description DESCRIPTIONHERE
Router(config-if)# ip address IPADDR SUBNETMASK
Router (config-if)#no shutdown (turns interface on)
59
is a hardware device that converts a digital data frame from the communications technology used on a local area network (LAN) into a frame appropriate to a wide- area network (WAN) and vice versa
CSU/DSU
60
If you intend to connect a router to a CSU /DSU, then the router's interface is a
DTE (also known as child)
61
How to configure serial interface
Router>
Router#config t
Router(config)#interface serial NUMBER
Router (config-if)#description DESCRIPTIONHERE
Router(config-if)#ip address IPADDRESS SUBNETMASK
62
The primary function of a computer network is to ________ a packet from a source station and ________ it to a destination station.
accept
deliver
63
Example routing protocols
```
(RIP)
(IGRP)
(EIGRP)
(OSPF)
(IS-IS)
```
64
Routing decisions are based on the data within
routing tables
65
Routing tables contain ...
- Data about the a router's local subnets - Data about adjacent (i.e. neighbor ) routers' subnets
66
indicate the optimal route each packet should take through the internetwork
Routing tables
67
Routing tables optimize routes based upon some performance criteria.
```
# of hops
Cost
Delay
Bandwidth
Throughput
```
68
Inconsistent routing tables will cause problems !
- Unsuccessful routing
- Ping Ponging
- Cycles
69
The routing table at node i says the route is through node j
The routing table at node j says the route is through node i
This is called
Ping ponging
70
Based on routing tables, the packet is passed among a subset of nodes
Cycles
71
Desirable Routing Algorithm Attributes
- Correct
- Simple
- Robust
- Stable
- Fair
- Optimal
72
A routing algorithm _______ work
Must
73
A routing algorithm should use a minimum number of resources or processing capacity at each router.
It should also place minimal burden on the bandwidth of links between routers.
Simple
74
- A routing algorithm must adapt to changing levels of traffic flow and find alternative routes when nodes /links fail , or links come back into service.
- A network is a “living entity!
Robust
75
A routing algorithm must adapt to changing levels of traffic flow and find alternative routes when nodes /links fail , or links come back into service.
- A network is a “living entity!
Robust
76
A routing algorithm must converge to a solution (i.e. the selection of a path) without excessive oscillation when adapting to changing loads and topologies.
Stable
77
- A routing algorithm should be able to provide the "best" routes that minimize the mean packet delay and maximizes throughput
- Routing algorithms are essentially optimization problems !!!
Optimal
78
We will define measures of performance through:
- # of hops
- Cost
- Delay
- Bandwidth
- Throughput
79
How long does it take to transmit a packet from source to destination
Delay
80
How much data is transmitted from source to destination
Throughput
81
What type of routing strategy to use?
- Static Routing
- Default Routing
- Random Routing
- Flooding Routing
- Dynamic/Adaptive Routing
82
routes are predefined and loaded into a router before any messages are transmitted
Static routing
83
send packets with a remote destination network not in the router table to the next-hop router
Default routing
84
You should only use default routing networks on "______” networks
Stub
85
- Place received packet on any router output line
| - Referred to as "Hot Potato" Routing
Random routing
86
Place received packet on all router output lines. Most dynamic of the four routing strategies
Flooding routing
87
routes are updated when nodes/links fail or the network changes
Dynamic/adaptive routing
88
Three types of dynamic/adaptive routing
- Distance Vector
- Link State
- Hybrid
89
A router calculates the best path between a source and a destination based on shortest hop count (i.e. distance)
Distance- vector routing
90
A router first exchanges information about connections within the internetwork , and then builds a topology table
Link state routing
91
Administrator is responsible for manually " setting uproutes between routers
Static routing
92
a numeric value routers use in order to select the best path when there are two or more different routes to the same destination from two different routing protocols .
Administrative distance
93
defines the reliability, or trustworthiness, of the routing information received on a router from a neighbor router
range [0 - 255]
Administrative distance
94
Three classes of dynamic routing algorithms
1. Distance Vector
2. Link State
3. Hybrid
95
Exhibits characteristics of both distance-vector and link-state algorithms
Hybrid
96
Rip routing iOS command
Network Router (config)#router rip Router ( config- router) #network A.B.C.D Router ( config- router) #version 2
97
is an address for a subnet similar to a subnet mask, but different
Wildcarding
98
Example of wildcarding using subnet 192.168.5.0/24
1st octet block size = 256 - 255 = 1 so wild card is 0
2nd octet block size = 256-255 = 1 , so wild card is 0
3rd octet block size = 256 - 255 = 1 so wild card is 0
4th octet block size = 256-0 = 256 , so wild card is 255
Wild card address is 0.0.0.255
99
OSPF Routing IOS commands
Router>enable
Router configure terminal
```
Router (config)#router
# Router (config-router) #network A.B.C.D area A#
```
100
EIGRP Routing iOS command
Router>enable
Router#configure terminal
Router ( config)#router eigrp
# Router (config- router) #network A.B.C.D
101
take in frames that arrive on active interfaces
Switch
102
The frame's source MAC address IS listed in the switch's MAC address table
The frame's destination MAC address IS listed in the switch's MAC address table
The switch forwards the frame out on the port associated with the frame's destination MAC address
103
The frame's source MAC address IS NOT listed in the switch's MAC address table
The frame's destination MAC address IS listed in the switch's MAC address table
The switch writes the source MAC address in the MAC address table and associates it with the interface that the frame arrived
The switch forwards the frame out on the port associated with the frame's destination MAC address
104
The frame's source MAC address IS NOT listed in the switch's MAC address table
The frame's destination MAC address IS NOT listed in the switch's MAC address table
The switch writes the source MAC address in the MAC address table and associates it with the interface that the frame arrived.
The switch floods the frame out on all ports except the port on which the frame arrived
105
A MAC address is associated with _______ Switch port/interface
only one
106
A switch port/interface can be associated with ___________ MAC addresses
two or more (many)
107
The frame's source MAC address and destination MAC address ARE BOTH listed in the switch's MAC address table AND associated with the same port
The switch filters ( i.e. drops ) the frame
