1/ Copy and paste the backup configuration directly to the device

                2/ Copy the configuration from a TFTP server to the device.

In both cases, make sure you save your configuration afterwards using either “copy run start” or “write”.

Below is an example of restoration from a TFTP server. You will notice the router name is “Router” – the default hostname for a router without configuration. After the restoration is completed, you will notice the hostname goes back to the configured value.

Related posts:

1. Upgrading the IOS on a Cisco Router
2. Backing Up the Running-Config and IOS
3. Navigating a Cisco device

The other major reason for IOS upgrades is to fix bugs that Cisco may have found in the software.

The 2 most common ways to do an upgrade are

                1/ Take the Flash card out the router, plug it into a card reader and paste the new file on the card. Replace the card in the router and reboot.

                2/ Copy the file over the network using a protocol like TFTP.

When copying the IOS over the network, the router will check to confirm it has enough storage space to accommodate the file. It will often ask to erase the flash before copying the new image. Before erasing the flash on the router, make sure there are no other files on the flash that you might need. If there are files that you will require, make sure you have made a backup of them before erasing!

Here are the steps for upgrading via the network.

1/ Run your TFTP server and confirm it’s hosting the IOS that you wish to upgrade to

2/ Configure the following on the router

 AOIP.ORG# copy tftp: flash:

Address or name of remote host []? 192.168.1.1

Source filename []? c1841-ipbase-mz.124-5b.bin

Destination filename [c1841-ipbase-mz.124-5b.bin]?

%Warning: There is a file already existing with this name

Do you want to over write? [confirm]

In the example above, I had chosen to upgrade to the same image that was already loaded on the router. Although not a practical solution, it does show the commands to upgrade.

Below you will see the different output when I chose a different file.

AOIP.ORG# copy tftp: flash:

Address or name of remote host [192.168.1.1]?

Source filename [c1841-ipbase-mz.124-5b.bin]? c1841.bin

Destination filename [c1841.bin]?

Accessing tftp://192.168.1.1/c1841.bin…

Loading c1841.bin from 192.168.1.1 (via FastEthernet0/0): !

%Error copying tftp://192.168.1.1/c1841.bin (Not enough space on device)

Again, I have received an error message, this time due to lack of free space on my flash card on the router. I would then have a chance to confirm there are no files on the flash that I need to keep before erasing the flash. If there are files I need to retain, make sure you back them up before erasing!

Make sure that you have already confirmed that the router physically has enough flash to be able to support the image you wish to install. You can see how much Flash is available and installed by using the ‘show flash:’ and ‘show version’ commands

Depending on the router model, you can erase the contents of the flash by typing

AOIP.ORG# erase flash:

OR

AOIP.ORG# erase nvram:

After the flash has been erased, you would then be able to copy the file from the tftp server.

Below is a live demo of an upgrade.

Related posts:

1. Backing Up the Running-Config and IOS
2. Restoring Cisco Router Configuration
3. Configuring DHCP on a Cisco router

It’s a logical statement but sadly one that many people only truly appreciate when it’s too late!

Two of the most important files on a Cisco router are the Running-Config which stores the current configuration of your router, and the IOS (The operating system) that your router needs to be able to boot.

It’s vitally important that a copy of both of these files is available at all times, and one of the easiest and quickest ways to keep these files from all your devices together is to copy them to a TFTP server. I use PumKIN as my TFTP server as it’s free, easy to use and does the job perfectly.

At the end of this post you will see a Live demo of how to copy the IOS and Running-config to a TFTP server running an IP address of 192.168.1.1.

Here is a breakdown of the configuration

AOIP.ORG# show flash

This will show you all the files that are currently stored in the Flash memory of the router. The file with a .bin extension is the IOS that we want to backup. You can copy this file name for use in the next step.

AOIP.ORG# copy flash: tftp:

This instructs the router I would like to copy data from the flash of the router to a tftp server.

Source filename []? c1841-ipbase-mz.124-5b.bin

You are prompted for the file name you wish to copy, you can paste the .bin file you have just copied.

Address or name of remote host []? 192.168.1.1

Specify the IP address of the TFTP server

Destination filename [c1841-ipbase-mz.124-5b.bin]?

The router will automatically prompt you to save the file with the same name as the source. You can change it here, or just press <Enter> to accept the file name.

At this point your router will start to copy the file. Once the file has finished copying, it will show you the details. In my case my router displays “13966524 bytes copied in 50.068 secs (278951 bytes/sec)”

You can backup your Running-Configuration very similarly, however replace flash: with running-config as seen below

AOIP.ORG# copy run tftp:

Address or name of remote host []? 192.168.1.1

Destination filename [aoip.org-confg]?

!!

784 bytes copied in 1.180 secs (664 bytes/sec)

Related posts:

1. Upgrading the IOS on a Cisco Router
2. Restoring Cisco Router Configuration
3. Navigating a Cisco device

There are 2 things that have to be in place before a password recovery can be done.
1/ Physical access to the router
2/ A console connection to the router

Here are the steps which need to be followed carefully. Some of these steps if not followed correctly, will wipe your router clean and leave you with a fresh router with NO configuration!

Firstly, make sure the console connection is working and that you are receiving output from the device.
Secondly, reboot the device by doing a power cycle (Turn it off and turn it back on again)
You will have to break the boot sequence by pressing <Ctrl>+C, you may have to do this several times to make sure the router receives your break signals at the correct time. This will force the router in rommon mode. From here you need to type the following

rommon 1> confreg 0×2142
This sets the routers configuration register to bypass the startup-configuration on boot up. The startup-configuration has the passwords in it, so by bypassing it, the router will look brand new and bring us to the “Would you like to enter initial configuration?” screen.

rommon 2 > initialize
This will reload the router
After the router has reloaded, you will be prompted with the “Would you like to enter initial configuration?” which you can bypass by pressing <Ctrl>+C
Continue with the following configuration

Router> enable
Router# copy start run

WARNING!!!!!!! – DO NOT DO THIS THE WRONG WAY OUT OF HABBIT. Typing copy run start will erase EVERYTHING on the router and you will have to rebuild the router from scratch!!!
This command will copy the Startup-configuration into the running-configuration. Since you are already in enable mode, you will not be prompted for a password even though the configuration has now been put back.

AOIP.ORG# conf t
AOIP.ORG (config)# enable password new
AOIP.ORG (config)# enable secret new
You are now able to change any password that you have forgotten since you are already in enable mode

AOIP.ORG (config)# config-register 0×2102
This puts the routers configuration register back to normal (boot from the startup config)

AOIP.ORG (config)# do show ip interface brief
You will notice that all interfaces are in an “administratively down” state

AOIP.ORG (config)# interface f0/0
AOIP.ORG (config-if)#no shut
AOIP.ORG (config-if)# interface eth 1/0
AOIP.ORG (config-if)# no shut
AOIP.ORG (config-if)# interface bri 0/0
AOIP.ORG (config-if)# no shut
AOIP.ORG (config-if)# exit
AOIP.ORG (config)# exit
AOIP.ORG # show ip int brief
After no shutting all interfaces, the router is back to normal operations.

AOIP.ORG # copy run start
After all your changes, it’s time to save the new configuration, with the new passwords.

AOIP.ORG # reload
Last but not least, reload the router so the configuration register can take effect. After reboot, you are back to a full working solution and the password has now been reset.

Below are 2 live demo’s. The first is the configuration needed in rommon, the second is after the router has been reloaded from rommon.

Related posts:

1. Setting the enable password and secret on a Cisco device
2. The difference between Run and Start and how to save!
3. Decrypting Type 7 Passwords (enable password)

On a Cisco router, the quickest way to see all lines as well as their status is by using the “show ip interface brief” command.

In the live demo below, you will see that I have used the “show ip interface brief” command and you will see that I have 5 interfaces on this router. FastEthernet 0/0, Serial 1/0, Serial 1/1, Serial 1/2 and Serial 1/3. You will also notice that none of the interfaces currently have an IP address configured on them, and under the Status column all lines are showing “administratively down” and under the Protocol column all lines are showing “down”

So firstly lets understand what the Status and Protocol columns mean, and what possible options there are associated with them.

Status                                                   Protocol

up                                                           up                          

This is what we are looking for, and indicates the interface is functioning correctly

down                                                    down                   

The line is not receiving a carrier detect, which could be the result of a telephone company fault, faulty cabling or hardware failure

up                                                           down                   

The local or remote routers have been misconfigured, the clock rate has not been defined, or there is a timing problem

up                                                           Up (looped)      

There is a loop in the circuit and you should contact your leased line provider

administratively down                  down   

The interface is still in ‘shut’ mode and needs to be ‘no shut’

You will also in the live demo, that I have issued the ‘no shut’ command on my Serial 1/0 interface, and after issuing the ‘show ip int brief’ command again the line now shows “up up”.

Related posts:

1. Configuring an IP address on a Cisco Device
2. Configuring VTY Access
3. The “do” command

The command to set the IP address, once in interface mode, is ‘ip address x.x.x.x z.z.z.z’ where x is the IP address, and z is the subnet mask. All interfaces on a router, by default, are in a shut state (off), to turn the interface on, we use “no shut” and similarly to turn it off again “shut”. Once the IP has been set, you can confirm the interface is live and that the IP has been accepted by using ‘show ip interface brief’. You will notice in the live demo below, that my interface was Serial 1/0 and the interface is now in a UP UP state.

Related posts:

1. The “do” command
2. Interface Status
3. Navigating a Cisco device

NOTE: If you are planning on sitting any Cisco exams, the simulators in the exam DO NOT support ‘wr’ and you have to use ‘copy run start’

In the live demo below, I have changed the hostname of my router from ‘AOIP.ORG’ to ‘AOIP’, you will notice when I looked at the running-config the change has happened, however when I looked at the startup-config, it is still set as ‘AOIP.ORG’. Only after I have saved my configuration does the change reflect in the startup-config.

NOTE: Save soon, and save often!

Related posts:

1. Navigating a Cisco device
2. Password Recovery Procedure for Cisco Routers
3. Banner – Message Of The Day (MOTD)

By NO means, is this a “Welcome” message, this should state your companies access rights policy and who should and should not be allowed to access the device. There are a few option available for configuring a message on a Cisco device all of which fall under the command ‘banner’. In the live demo below I have shown an example of configuring a MOTD (message of the day), that will be displayed when you connect to the router or switch.

From global configuration mode, you can enter the command ‘banner’ if you were to put a ‘?’ afterwards, you will see all the banner types supported, including ‘motd’. When configuring any banner, you need to select a delimiting character to mark the start and end of the banner. In most cases I recommend using the ‘#’ symbol. This allows us to enter the command ‘banner motd # <enter>’ which puts us into a banner menu. You can then type or paste any message that you would like to appear, pressing <enter> again will move you to a new line, and the device will only stop gathering you text once you submit another ‘#’ to mark the ending of the message.

Related posts:

1. Configuring VTY Access
2. Setting the enable password and secret on a Cisco device
3. Navigating a Cisco device

In this article I’m going to focus on the enable password and enable secret command and show some differences between them.

In order to configure the enable passwords we first need to be in global configuration mode, from there we can either issue the ‘enable password aoip’ command, where ‘aoip’ is our chosen password. Or we can enter the ‘enable secret aoip’ command. The big difference between the 2 commands is that enable password is not encrypted by default whereas the enable secret is.

If we do a ‘show run’ on our device after setting the password and secret we can see that the enable password, as well as the line vty and console passwords are all readable in clear text. In order for us to encrypt ALL passwords on the Cisco devices, we can issue the command ‘service password-encryption’ from global configuration mode.

Below is the live demo showing the ‘enable password’, ‘enable secret’ and ‘service password-encryption’ commands.

Related posts:

1. Decrypting Type 7 Passwords (enable password)
2. Password Recovery Procedure for Cisco Routers
3. ‘Login local’ on a Cisco Router

In order to connect your computer to a Cisco device using the console port, you need a Console cable, also known as a roll-over-cable. The pins on the cable are totally reversed (rolled over), so pin 1 on side A goes to pin 8 on side B, pin 2 goes to pin  7, 3 – 6, 4 – 5, 5 – 4, 6 – 3, 7 – 2, 8 – 1. Both ends of the cable use RJ-45 connectors, one of which will be plugged into the Cisco device’s Console port, the other end into your computer, however you will require an adapter for your computer which are easy to get and come in many forms. RJ-45 to RS-232 (COM Port), RJ-45 to USB etc. (You can also by console cables that have a RJ-45 connector on side A and a RS-232 connector on side B, no adapter is therefore required)

Even though the console connection is enabled by default and does not require any configuration, there are a few things that we would like to configure on the port, like a password. To configure the console connection we need to be in global config mode and issue the ‘line console 0′ command. Since there is only ever one console port on a device, and since the numbering always starts with ’0′, the command will always be ‘line console 0′

In the first live demo below, we see the following commands be configured for the console port.

1/ ‘exec-timeout 0 0′ – This command sets how long the console connection can be open and idle before it auto logs out. The two values are for ‘hours’ and ‘minutes’ in my example I have set 0 hours, and 0 minutes, which disables the auto logout feature.

2/’logging synchronous’ -This prevents your text from been interrupted by system messages. The second live demo below demonstrates this. I was typing “interruption of text” and you will notice that when the system message appears on the screen while I’m typing, my text gets added to the end of the system message. The third live demo below, shows what happens when logging synchronous is enabled… no interruption.

3/’password aoip’ – This sets the password of the console port to ‘aoip’

4/ ‘ login‘ – Enforces password checking on the console port. When you now connect to the Cisco Device via the Console port, you will be prompted for the password, in this case ‘aoip’

Related posts:

1. Setting the enable password and secret on a Cisco device
2. Configuring SSH (Secure Shell) on a Cisco device
3. Configuring an IP address on a Cisco Device