Cisco Systems

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According to Wikipedia, “In computer networking, a single layer-2 network may be partitioned to create multiple distinct broadcast domains, which are mutually isolated so that packets can only pass between them via one or more routers; such a domain is referred to as a Virtual Local Area NetworkVirtual LAN or VLAN.”

VLAN’s simplify network management, limit the size of a broadcast domain and improve network efficiency. VLANs are of two types.

  • Static VLAN
  • Dynamic VLAN

In a static VLAN, we assign specific ports to a specific VLAN. whereas in dynamic VLAN we assign MAC addresses to a specific VLAN. In this article we are going to see how to create and configure a static VLAN. We are going to create three VLANs and assign ports to them. For this example, we will create three VLANs named Java, SAP and HR.

vlan1

 

We need to be in global configuration mode to create VLANs. The command “vlan 2″ assigns number 2 to the VLAN we are going to create. We can assign any number from 2 to 4094 to the vlan. The command “name java” names our vlan as java. Similarly we can create the vlans SAP and HR.  Before assigning ports to the VLAN let’s see the port states in our switch.

vlan2

 

We can see above that all the ports of the switch are members of VLAN 1. VLAN 1 is a special purpose VLAN used for administration. It is the only precreated VLAN on the Cisco switch. All ports are members of this VLAN by default. So when you are assigning a port to a specific VLAN, you are just changing the port from VLAN1 to that VLAN.

Now let’s assign ports to the VLANs we just created. First,  let’s assign three ports to the VLAN java.

vlan3

 

The “interface fastethernet 0/1″ command selects the fastethernet port 1. The “switchport access vlan2″ command assigns this port to VLAN java. Similarly we can add the fastethernet ports 2 and 3 to the vlan 2. Now let’s see the port states once again.

vlan4

 

We can see that the first three fastethernet ports have been assigned to the VLAN java. Now we will assign fastethernet ports 4 and 5 to VLANs SAP and HR respectively.

vlan5

 

This is how our network  will look like if we connect the host devices.

vlan6

 

And our port states will look like this.

vlan7

 

Good evening friends, Today we will see how to configure passwords on Cisco routers and switches. Cisco devices have four types of passwords.

  • Console password : Used to set password for the console access.
  • Auxiliary password : It is used to set password to auxiliary port ( if the switch has one.)
  • VTY lines password : Used to set password for  for telnet and ssh access.
  • Privileged password : Used to set password for privileged access to the switch.

I am not going to show you how to set up auxiliary password here. To see how to set up console password and VTY lines password, go here.

Privileged mode of a Cisco device has some advanced IOS commands that can have disastrous consequences if used by wrong hands. So it is very important to set up a password to access privileged commands. Use the following commands

ciscopass1

 

The “enable” command takes us into privileged mode. The “conf t” mode takes us into global configuration mode which pertains to the configuration settings of the whole switch. The “enable password”  sets a password for the privileged mode. ‘123456’ is the password. The “exit”  command takes us out of the privileged mode. To see if a password has been set for the privileged mode, try entering into privileged mode by typing “en” command. We can see that it prompts us for the password.

I am self learning for CCNA. A few months back, I got a thought if we can simulate routers in Vmware Workstation. While I was searching for it I found a different solution, GNS3. After simulating routers in GNS3 and practising CLI interface, I had another idea if we can simulate CISCO Graphical User Interface on our PC. This article is  result of that.

In this article, we are not only going to see how to connect Vmware and GNS3 but also see how to simulate CISCO Graphical user Interface (GUI). For this I use,

1. Vmware Workstation 9.

2. Windows XP as Guest OS.

3. Cisco Security Device Manager v25.

4. GNS3.

5.  C7200 Router Image.

Open Vmware Workstation. On the menu Select “Edit>Virtual Network Editor”. On the Virtal network editor, click on “Vmnet1″ network. It is a default Host-only type network adapter of Vmware. Observe its settings. Enable DHCP server.

vmgns1

 

Install Windows XP as a guest. On its virtual machine settings, change the network adapter to “Vmnet1″.

vmgns2

 

Power on the machine. Install Cisco SDM ( I leave the getting Cisco SDM part to you ). Open CMD and type “ipconfig” to see its IP address. Take note of this.

vmgns3

Open GNS3. Click on “Browse all devices”.

vmgns4

 

Select Router “c7200″ and drag it to the workspace. Do the same with “Cloud”.

vmgns5

 

Close the All Devices tab. Right click on the Cloud.  Select “Configure”, a ‘node configurator’ window will open. On this window, click on “C1″.

vmgns6

On the NIO Ethernet tab, in the “Generic Ethernet NIO tab” dropdown menu, select our network adapter (Vmnet1) from the dropdown menu and click on “Add”. Click on “OK” to close the window.

vmgns7

Right click on the router. Select “Configure”, click on “R1″. Select slots tab. In the Slot 1 dropdown menu, select “PA-4E”. Click on Apply an close the window. The selection PA-4E creates four Ethernet ports on the router. Right click on the router and start the router.

vmgns8

Add a link from “cloud( Vmnet1)” adapter to the “e1/0″ port on the router.

vmgns9

Hover your mouse over the router. We can see all the ports.

vmgns10

Similarly hover your mouse over the cloud to see its connections.

vmgns11

 

Right click on the router and select “Console”. In the global configuration mode, type the following commands.

ip http server”

ip http secure-server”

These commands set up http and https servers respectively which are needed for Cisco SDM.

vmgns12

Type the command “interface Ethernet 1/0″. We are entering into specific configuration mode of our connected interface. Type the command “ip address 192.168.10.3 255.255.255.0″. This sets the interface IP address and subnet mask. Make sure the router IP address is in the same subnet as that of our guest OS in Vmware workstation. Type “no shut” and exit to the privileged mode.

vmgns13

Let’s ping our guest from the router. to ensure that we are connected to Vmware Guest.

vmgns14

Since success rate is 100%  we have successfully connected Vmware and GNS3. Now let’s do the Cisco SDM part. On our Guest machine click on Cisco SDM. A SDM launcher window will open. Type the IP address of the router and click on Launch.

n16

 

Internet Explorer will open as below. Make sure Internet Explorer is configured to allow pop ups and to allow Activex to run from the computer.

n17

 

After some time the following popup will open. Don’t close it.

n18

 

Then we might see a certificate warning. Click on Yes.

n19

 

After some processing, Cisco SDM will open.

n20

 

We have successfully simulated Cisco GUI on our PC. Happy practice friends.

Cisco IOS is the internetwork operating system of both the Cisco switches and routers. It has two interfaces command line interface(CLI) and Graphical User Interface(GUI). Since CCNA exam will surely test your knowledge on these interfaces, it is important to get familiar with them.

Cisco’s IOS command-line interface (CLI) is a text-based interface integrated with the IOS. When a switch or router boots up, the IOS loads the startup configuration from NVRAM and displays the IOS prompt, waiting for commands. We can enter the IOS commands at the IOS prompt.

In this article, we will see various command line modes on Cisco routers and switches. For this, we are going to use Packet Tracer. To see what is Packet Tracer and how to install it in both Linux and Windows, go here. For a startup guide on Packet Tracer, see here. Open Packet Tracer  and select a Cisco 2960 switch.

cclm1

 

Hover on the switch to see its ports.

cclm2

Select a Computer from the End Devices and connect them with a Console wire. What we are simulating here is connecting to the switch from a PC through console.

cclm3

 

Click on the Host device( Computer ). On the window that opens, click on Desktop tab and Click on Terminal.

cclm4

The console opens with the switch booting. Switch finishes its booting operation and loads  into user EXEC mode.

cclm5

Coming to the modes of Cisco IOS, the Cisco IOS has five command line modes.

  • Setup mode
  • User EXEC mode
  • Privileged EXEC mode
  • Global configuration mode
  • Specific Configuraton mode

Setup mode

Setup mode is the initial configuration mode of Cisco switches and routers. They start in setup mode when no startup configuration exists in NVRAM. After completion of the setup mode,  the Cisco IOS transitions to user EXEC mode.

User EXEC mode

The user EXEC mode is the normal operation mode on Cisco switches and routers. The Cisco IOS user EXEC prompt is the switch or router name followed by the ‘greater than’ character >. See all the commands available in user EXEC prompt by typing ‘?’

cclm6

 

Privileged EXEC mode

Privileged EXEC mode is the advanced operation mode of Cisco IOS. It has been designed to restrict access to IOS commands that can have adverse effects on the Cisco device and its configuration. To enter privileged EXEC mode type “enable” or “en” .Privileged EXEC prompt is comprised of the switch or router name followed by the # character. To exit the privileged EXEC prompt type “disable”.

cclm7

 

To see the commands available in privileged EXEC prompt, type ?.

cclm8

 

Global Configuration mode

The global configuration mode is comprised of commands pertaining to the entire Cisco device. In other words, if we need to execute commands to modify the behavior of either the whole switch or the whole router we need to set the IOS in global configuration
mode. Global configuration mode can only be enabled from  privileged
EXEC mode by typing config t” or “conf t”. The prompt in this mode is comprised of the device name followed by “(config)#”.

cclm9

 

See the commands available in this mode by typing ‘?’. If we need to execute a command not available in the global configuration mode we should prefix the command by “do”.

cclm10

 

Specific configuration mode

The specific configuration mode is used for commands that affect the configuration of either just one part or range of components of the Cisco device. Suppose we want to work on a few interfaces (or ports) on our switch or router we need to enable specific configuration mode. We can enable specific configuration mode only from the global configuration mode by selecting the components we want to work with. The prompt in this mode is comprised of the router or switch host name followed by “(config-<component>)#”.

Let’s select interface fastethernet 0/1 by typing “interface fastethernet 0/1″. 

cclm11

If we want to run a command not available in specific configuration mode prefix the command by do”. For example, run the command “do show running-config” in specific configuration mode.

cclm12

 

We can exit from global configuration mode and specific configuration mode by typing “exit”.