Page 1 CCNA study guide.docx CCNA study guide.docx.pdf
.CCNA
Week 1 (Networks, Basic configuration)
1. Cisco Foundations - Configuring a Cisco Device - Programs and Console Connections
Starts talking about console cables, the name of the entry that you plug into the console cable is
RJ-45. He recommends the site monoprice to buy cheap cables.
Connecting to the cisco switch
1. Get a console cable
2. Plug the serial end into the back of your pc
3. Plug the RJ-45 end into console port in switch
After those steps you need to open a terminal program, some examples of programs that can be
used in that case are:
- Putty (free)
- Tera term (free)
- SecureCRT($100 but the best)
- Minicom (free) (linux and apple)
Inside the program the recommend configurations are:
The serial line usually is COM1, other than some situations with USB to serial adaptors, that can be
seen in the computer manager menu in ports.
Speed is 9600, Data bits 8, Stop bits 1 and Paty and Flow control are none.
2. Working with the Cisco IOS
The Internetwork Operating System (IOS) is a command-line method of configuring a Cisco device, it
is a software that is consistent through nearly all Cisco devices. Have the advantage of “learn it
once” and use it many times and is more powerful than any graphic interface.
Understanding IOS Command modes
Switch> - User mode
Switch# - Privileged mode
Switch(config)# - Global configuration mode
-2026 CCNA study guide.docx CCNA study guide.docx
,Page 2 CCNA study guide.docx CCNA study guide.docx.pdf
Knowing the modes of your Cisco device is more important than knowing what commands to type.
User mode have limited options
Privileged mode have access to see all the information but can’t change anything
Global configuration is where you can change/configure everything, but all the changes are globally
affected.
When you want to change the configuration of a specific part you have to move to a specific
interface or line
All most used Commands are described in the end.
You can use a shortcut of any command as long as it has enough characters to be the only one
starting with those letters. Like enable can be used as “en”.
3. Base Configuration
Performing an initial configuration
Hostname “name” - To give a hostname to device
Negating commands – just put the word “no” before a command to remove the command used, ex:
“no hostname”, would remove the hostname that was inserted before.
Passwords
There are 3 different passwords to be enable in the device:
- Console password: Set a password to access any mode. To enable a console password, you
need to move to Global conf and from there go to “line console 0” that is the line for the
console. After being inside the line you can just type “password WORD” to define a
password and after type “login” to enable it, otherwise will not be enabled. Because even if
the password is set, if no login is required so won’t be needed to use the password.
- Telnet/SSH password: The purpose of setting a telnet/SSH password, is about the security to
configure the switch from distance without letting other people access the same. To
-2026 CCNA study guide.docx CCNA study guide.docx
,Page 3 CCNA study guide.docx CCNA study guide.docx.pdf
configure a telnet password, it is needed to move to the line vty, the difference between the
line console to the line vty is that the line console there is only 1 port, the port 0. and the
line vty depends on the cisco device but have an average of 16 lines, that can be configured
individually together.
So, the command line is line “vty STARTING line ENDING line”, if you just want to configure
line 0, would be “line vty 0 0”, but if you want to configure line 0-15 would be “line vty 0 15”.
And after being inside those lines you can set the password with “password WORD”, in the
line vty you don’t need to use the login command.
- Enable password: This is to set a password if someone wants to move to privileged mode.
Since this is just one for the hole device, you don’t need to move to any lines, this can be
done in the global conf mode. There are 2 ways of setting a enable password, with the
command enable password and with enable secret, the difference between then is that
when show running conf, the enable password will show the password in plain text and the
secret will be encrypted. So always prefer to use enable secret.
-
- VTY = Virtual Terminal
-
Banner
Banner motd +WORD+
Saving configuration
There are two ways of saving your changes and configurations, the first one is with “run” that saves
in the RAM, if the switch needs to be power down, all the savings in that will be lost. The second way
is through “start” that saves in the nvram (non-volatile ram) that everything is saved even if you
power down the switch.
The command to save is copy running config startup config, another command that is shorter and
can be used in 99% of cisco devices is write memory, that can be just “wr”.
4.Configuring SSH, User Accounts, and Password Encryption
Configuring SSH on a Cisco device
1. Configure your hostname
2. Configure a domain name, using the command “ip domain name WORD”
3. Generate encryption keys, using the command “crypto key generate rsa” and then select the
number of bits that will be used to generate the key
4. Enable SSH v2, using the command “ip ssh version 2”
5. Create a username with the command “username WORD secret WORD”
6. Choose to allow telnet and SSH, using the command “transport input telnet ssh”
7. Enable local login, go to “line vty 0 15” again and use the command “login local” so the
system can use the username detail to log in the SSH, otherwise will not work because the
system is programmed to only use the password without a username.
-2026 CCNA study guide.docx CCNA study guide.docx
, Page 4 CCNA study guide.docx CCNA study guide.docx.pdf
Week 2 (OSI, Binary)
1.Speaking Binary
Reviewing Ip Basics
There are 3 different classes of subnet masks:
A – 255.0.0.0
B – 255.255.0.0
C – 255.255.255.0
When the ip address is combined with the subnet mask, defines the network and host parts.
The network part is where are the 255 and the hosts the 0s.
The biggest network that you want to create is with 500 hosts.
Operates in layer 3(Network layer)
To calculate what the number is in binary, first you need to write a table as below:
128 64 32 16 8 4 2 1
Starting from the left until the right, seen if the number above fits in the number that you want to
put in binary, if is bigger, put 0 and go to the next, if it is smaller the put 1, decrease the amount
from the original value and go on until the original number comes to 0.
Ex: 12
00001100
220
11001000
With 8 bits you can convert a number until 255.
2. Cisco Foundations - Network Components, Diagrams, Cables, and Speed
Just information about how the network works.
3. Cisco Foundations - Speaking the Language of the OSI Model
The OSI model is a standardized architecture defining network communication.
The nugget is all about the understanding of the OSI model, if you have any doubts about the layers,
go back to this nugget and write everything about it. Follow the OSI model with some examples
below:
-2026 CCNA study guide.docx CCNA study guide.docx
.CCNA
Week 1 (Networks, Basic configuration)
1. Cisco Foundations - Configuring a Cisco Device - Programs and Console Connections
Starts talking about console cables, the name of the entry that you plug into the console cable is
RJ-45. He recommends the site monoprice to buy cheap cables.
Connecting to the cisco switch
1. Get a console cable
2. Plug the serial end into the back of your pc
3. Plug the RJ-45 end into console port in switch
After those steps you need to open a terminal program, some examples of programs that can be
used in that case are:
- Putty (free)
- Tera term (free)
- SecureCRT($100 but the best)
- Minicom (free) (linux and apple)
Inside the program the recommend configurations are:
The serial line usually is COM1, other than some situations with USB to serial adaptors, that can be
seen in the computer manager menu in ports.
Speed is 9600, Data bits 8, Stop bits 1 and Paty and Flow control are none.
2. Working with the Cisco IOS
The Internetwork Operating System (IOS) is a command-line method of configuring a Cisco device, it
is a software that is consistent through nearly all Cisco devices. Have the advantage of “learn it
once” and use it many times and is more powerful than any graphic interface.
Understanding IOS Command modes
Switch> - User mode
Switch# - Privileged mode
Switch(config)# - Global configuration mode
-2026 CCNA study guide.docx CCNA study guide.docx
,Page 2 CCNA study guide.docx CCNA study guide.docx.pdf
Knowing the modes of your Cisco device is more important than knowing what commands to type.
User mode have limited options
Privileged mode have access to see all the information but can’t change anything
Global configuration is where you can change/configure everything, but all the changes are globally
affected.
When you want to change the configuration of a specific part you have to move to a specific
interface or line
All most used Commands are described in the end.
You can use a shortcut of any command as long as it has enough characters to be the only one
starting with those letters. Like enable can be used as “en”.
3. Base Configuration
Performing an initial configuration
Hostname “name” - To give a hostname to device
Negating commands – just put the word “no” before a command to remove the command used, ex:
“no hostname”, would remove the hostname that was inserted before.
Passwords
There are 3 different passwords to be enable in the device:
- Console password: Set a password to access any mode. To enable a console password, you
need to move to Global conf and from there go to “line console 0” that is the line for the
console. After being inside the line you can just type “password WORD” to define a
password and after type “login” to enable it, otherwise will not be enabled. Because even if
the password is set, if no login is required so won’t be needed to use the password.
- Telnet/SSH password: The purpose of setting a telnet/SSH password, is about the security to
configure the switch from distance without letting other people access the same. To
-2026 CCNA study guide.docx CCNA study guide.docx
,Page 3 CCNA study guide.docx CCNA study guide.docx.pdf
configure a telnet password, it is needed to move to the line vty, the difference between the
line console to the line vty is that the line console there is only 1 port, the port 0. and the
line vty depends on the cisco device but have an average of 16 lines, that can be configured
individually together.
So, the command line is line “vty STARTING line ENDING line”, if you just want to configure
line 0, would be “line vty 0 0”, but if you want to configure line 0-15 would be “line vty 0 15”.
And after being inside those lines you can set the password with “password WORD”, in the
line vty you don’t need to use the login command.
- Enable password: This is to set a password if someone wants to move to privileged mode.
Since this is just one for the hole device, you don’t need to move to any lines, this can be
done in the global conf mode. There are 2 ways of setting a enable password, with the
command enable password and with enable secret, the difference between then is that
when show running conf, the enable password will show the password in plain text and the
secret will be encrypted. So always prefer to use enable secret.
-
- VTY = Virtual Terminal
-
Banner
Banner motd +WORD+
Saving configuration
There are two ways of saving your changes and configurations, the first one is with “run” that saves
in the RAM, if the switch needs to be power down, all the savings in that will be lost. The second way
is through “start” that saves in the nvram (non-volatile ram) that everything is saved even if you
power down the switch.
The command to save is copy running config startup config, another command that is shorter and
can be used in 99% of cisco devices is write memory, that can be just “wr”.
4.Configuring SSH, User Accounts, and Password Encryption
Configuring SSH on a Cisco device
1. Configure your hostname
2. Configure a domain name, using the command “ip domain name WORD”
3. Generate encryption keys, using the command “crypto key generate rsa” and then select the
number of bits that will be used to generate the key
4. Enable SSH v2, using the command “ip ssh version 2”
5. Create a username with the command “username WORD secret WORD”
6. Choose to allow telnet and SSH, using the command “transport input telnet ssh”
7. Enable local login, go to “line vty 0 15” again and use the command “login local” so the
system can use the username detail to log in the SSH, otherwise will not work because the
system is programmed to only use the password without a username.
-2026 CCNA study guide.docx CCNA study guide.docx
, Page 4 CCNA study guide.docx CCNA study guide.docx.pdf
Week 2 (OSI, Binary)
1.Speaking Binary
Reviewing Ip Basics
There are 3 different classes of subnet masks:
A – 255.0.0.0
B – 255.255.0.0
C – 255.255.255.0
When the ip address is combined with the subnet mask, defines the network and host parts.
The network part is where are the 255 and the hosts the 0s.
The biggest network that you want to create is with 500 hosts.
Operates in layer 3(Network layer)
To calculate what the number is in binary, first you need to write a table as below:
128 64 32 16 8 4 2 1
Starting from the left until the right, seen if the number above fits in the number that you want to
put in binary, if is bigger, put 0 and go to the next, if it is smaller the put 1, decrease the amount
from the original value and go on until the original number comes to 0.
Ex: 12
00001100
220
11001000
With 8 bits you can convert a number until 255.
2. Cisco Foundations - Network Components, Diagrams, Cables, and Speed
Just information about how the network works.
3. Cisco Foundations - Speaking the Language of the OSI Model
The OSI model is a standardized architecture defining network communication.
The nugget is all about the understanding of the OSI model, if you have any doubts about the layers,
go back to this nugget and write everything about it. Follow the OSI model with some examples
below:
-2026 CCNA study guide.docx CCNA study guide.docx
