Vm Windows 10 is not accessible from GNS3 Problem with Virtual Machine is not getting IP from DHCP in GNS3

How to Connect Windows 10 Virtual Machine with GNS3 1.3.9:

You can see the following Video for connecting VM to router in GNS3:




If you are having difficulty while connecting a VM to GNS3 you may check the following:


1. Open the VirtualBox, goto adapter setting and select 'Not attached' 
2. If the ping from router to VM machine is not successful then turn off windows 10 firewall.
3. if you want to give the IP address to VM via DHCP configured on gns3 router then make sure you have disable all other DHCP in the network.



In case of any issue, you can ask question in comment.

DHCP lab in GNS3 | How to Configure DHCP on Cisco Router

Cisco DHCP Configuration | How to assign automatic IP address from Cisco Router:

In this article I will show you how to configure and enable DHCP (Dynamic Host Configuration Protocol) on Gns3 router. For this lab I have Create the following lab in which I have configure a router (DHCP Server) as DHCP server where as I used the two DHCP clients which will obtain the IP address automatically from DHCP server. These DHCP clients include a router (which is configured like a PC) and a VM machine.  You can visit How to connect windows VM to Gns3 & installation of windows 10 on Virtualbox for more detail.



Following configuration are required for making the Router as DHCP server.

DHCP server (R1) Configuration:
R1#enable
R1#Configure t
R1 config)#ip dhcp pool ipranges
R1(dhcp-config)# network 100.1.11.0 255.255.255.0
R1(dhcp-config)#dns server 100.1.11.1
 R1(dhcp-config)#default-router 100.1.11.1
R1(dhcp-config)#lease 10 (this command will set the IP lease for 10 day, view more Cisco Commands)

How to exclude the IP addresses from DHCP range


R1(dhcp-config)#ip dhcp excluded-addresses 100.1.11.20 100.1.11.31

Following are the configuration required on router which will act as DHCP client.

PC2 Configuration:
PC2#enable
PC2#Configure t
PC21#no ip routing
PC2#inf f0/0
PC2#ip address dhcp
 PC2#no shutdown

VM win 10 DHCP client configurations:

Simple power on the VM host in DHCP and set the network adapter setting to obtain the IP automatically. Check the following images:




How to test DHCP configurations:

On DHCP server use the following command for confirming DHCP configurations
show ip dhcp binding
Following will be the output in our case.


Other command that you can use is:
show DHCP neighbor.

GNS3 Tutorials for beginners | How to getting start with GNS3

GNS3 is one of the famous software for simulating the network devices. It is important for a networks Engineer or networks profession that he can create and simulate different network scenarios using GNS3.



This article is divided into different sections and design for both beginners and advance level GNS3 users.

GNS3 Tutorial for begginers:

If you are newer to GNS3 you can start working on GNS3 with the following tutorials:







GNS3 Labs & Tutorials

Following are some network labs that you can create with GNS3.

Cisco Route filtering




Use Juniper on GNS3

GNS3 Tutorials for CCNA:

Following are some gns3 labs which are useful for CCNA preparation.



Basic OSPF configruations


GNS3 video tutorials

Create Vlan with GNS3



Gns3 installation on ubuntu 



CCDA Intro freeTraining and tutorials 



GNS3 Gerneral issue and troubleshooting:


Cisco Basic Commands list for beginners | Cisco command levels EXEC Modes

Cisco IOS command level and their Basic Commands:

This article has basic Cisco commands, for more commands and details you can visit Cisco.com.

What are Cisco command levels EXEC Mode and how to access them:

With Cisco command levels EXEC Mode you can control user privileges. These user privilege controls can be given through password.  There are three command levels in all Cisco IOS devices. In each command level you have specific privileges and control. These commands Level are as under:
  •  User Mode
  • Privileged EXEC  Mode
  • Global configuration Mode

Cisco User Mode Cisco:

In user EXEC mode you can execute limited array of show commands, basic reachability tests, such as ping and traceroute, as well as other ways of viewing configurations and status info of a Cisco device without the ability to make changes. This command level is represented by symbol “>”, by using command you can “enable” you can go to next mode i.e. privileged EXEC mode.

Cisco Privileged EXEC Mode

Privileged EXEC mode is represented by symbol “#”.

This mode is for users that have been some admin privileges and need to make changes, but in this mode most of commands are related to view/show configurations and debugs.
In privileged EXEC Mode most of command show the status of cisco devices, module and startup, running configurations and configurations of different protocols.

Cisco Global Configuration Mode

This mode is for administrator and power user, from this mode you can configure your Cisco device can configure different Protocols. Some of common commands for configurations of this mode are as under.

You can access or go to global configuration mode by using command “configure terminal” when you are in Privileged EXEC mode.
R1>
R1>enable                                          Entering into Privileged EXEC Mode
R1#configure terminal                   Entering into Global Configuration Mode
R1(config)#

Note: In this article all Cisco commands are represented with purple color.

Example of Commands in Privileged EXEC Mode:

How to Check the IOS/hardware version of Cisco Device:

R1#Show Version 
Show version command will displays the configuration of the system hardware, the IOS version, and the names and sources of configuration files and the boot images. This command also displays information about how the system was last started and how long the router has been running since that start.

How to check all running configurations of Cisco Device:

Show running-config
This command will show all the configuration which are configure on Cisco device. You view output of show running-config

How to check the vlan details on Cisco:

Show Vlan
Click here to see the Outputof show vlan

How to check detail of specific interfaces on Cisco:

Show interface <interface name>
Command Example: show interface f0/0 (this command will show the detail of interface fastEthernet 0/0) 

How to check syslog errors:

show logging
show logging command displays the state of syslog error and event logging, including host addresses, and whether console logging is enabled. View output of show logging

How to check running process on Cisco Device:

show Processes 
This command will displays information about the active processes.

How to check the memory used by running process on Cisco:

show Processes memory
This command will displays the amount of memory used. See
output of Show processes memory.

How to check Routing table on Cisco Router/Switch:

show ip route
Above command will show all dynamic and static routes on Cisco Device. A output of show ip route.
show ip route OSPF
Command will show all OSPF routes.
show ip route RIP
Command will show all RIP routes.
Show ip route EIGRP
This command will show all EIGRP routes.

How to check all interfaces details:

show interfaces
This command displays statistics for the network interfaces. Output of this command include following details
         i.            UP/down state of interface
       ii.            MAC Address
      iii.            IP address
     iv.            MTU ,BW Delay, duplex type of interfaces
       v.            Queueing strategy
     vi.            Packet send/received
Click here to see the Outputof show interfaces

How to check the status of all interfaces on Cisco:

Show ip interface Brief
This command will show you the IP addresses, interfaces status (up/down), protocol status (up/down), you can view output of Show ip interface Brief from here.

Check neighbors detail and routing information | Cisco CDP commands    

 show cdp interface   
  show cdp neighbors [Detail]   
  show cdp entry Router 
 Ip domain-Lookup nsap    
 Show hosts    

Some other Examples of show commands:

Following are some others show command which are self-explanatory you can try these command on your Cisco device and view their output.
Show clock
Show controllers
Show mac-address-table 
Show memory
Show privilege
Show protocols
Show startup-config
Show Flash 
Show spanning-tree


Examples of Global configuration Commands:

 To enter in Global configuration mode type: config terminal. Global configuration mode is often used to configure the network Commands.

Set hostname of Router:

Router(config)#hostname <distinguished name>
Command Example: Router (config)# hostname R1 (This command will set the router name to R1)

How to set banner message:

banner motd <banner start identification> banner message <banner end identification>
Command Example:
banner motd #Unauthorized access to this device is prohibited!#    
Above command with set the banner to "Unauthorized access to this device is prohibited" 

How to set IP address to Cisco interface:

Router(config)#  Interface <port number >
Router(config-int)# ip address <ip address number>
IP address Command Example:
 Router(config)#interface f0/0
Router(config)# ip address 176.16.32.1 255.255.255.0
(This will set the IP address 176.16.32.1/24 to interface f0/0)
How to up/on the Cisco router interface:
Router(config)#interface f0/0
Router(config-int)# no shutdown 
(above command will change the status of interface fo/o to active/up/ON)

How to set the interface speed:

Interface console type the following commands for configuring interface speed.
switch(config-if)# speed{10|100|auto

R1(config)#interface f0/1
R1(config-if)#speed 100
Above commands will configure the speed of 100MBs to interface f0/1.

How to set enable password on Cisco:

Router(config)#  Enable Password <password>
Enable password Command Example:
 Router(config)# Enable Password Cisco
(This will Establishes a enable password to Cisco)

How to set Telnet password on Cisco:

Router(config)#line vty 0 4
Router(config-line)#login
Router(config-line)#password cisco
(Above command will create a Telnet password to Cisco)

Cisco IP routing Commands:

How to set the static routing:   
Router(config-router)#ip route [destination_network] [mask] [next-hop_address
Static route command example:
Router(config-router)#ip route 210.22.22.2 255.255.255.0 192.168.0.1
Above command will set a static route for network 210.22.22.0. See static routing on gns3.

How to set the default route on Cisco Router    

Router(config)#ip default-network< network number >   
Command Example: ip default-network 192.168.1.1

How to configure dynamic routing with Rip on Cisco:

Router(config)#Router rip    
Router(config-router)#Network <Network ID> 
Router(config-router)#Network 192.168.1.0
See more for configuration command example of RIP in Cisco from here.  

How to configure OSPF on Cisco:

Router(config)#Router ospf process ID
Router(config-router)#Network <Network ID> <mask> area <area ID>

Router(config)#Router ospf 1
Router(config-router)#network 10.0.0.0 0.0.0.255 area 0
Above command will advertise the network 10.0.0.0/24 in area 0.

How to configure access-list on Cisco:

Access-List <access number> {permit | deny}  <IP address to block>

for more details Access list in Cisco

Cisco Switching Commands:

How to crate Vlan on Cisco: 
switch(vlan)# vlan <vlan-num> name <vlan name>
 switch(vlan)# vlan 10 name marking
Above command will create vlan 10 with name marketing.
How to set access port: 
switch# configure teriminal 
switch( config)# interface fo/o
 switch(config-if)# switchport mode access 

How to assign vlan to interface in Cisco:
switch( config)# interface <interface name/number>
switch(config-if)# switchport access vlan <vlan-num> 
 Command Example:
switch( config)# interface  f0/0
switch(config-if)# switchport access vlan 10
Above command will add interface f0/0 to vlan 10.

 How to create trunk port: 

After selecting the interface mode type the following commad.
switch(config-if)# switchport mode trunk 

How to allow the specific Vlans on Trunk Port:

switch(config-if)# switchport trunk allowed vlan < vlan-list>


Cisco Daily used commands:

Cisco Connectivity Test Commands:

Ping host name / IP address    
R1> ping 10.0.0.1
traceroutehostname / IP address of destination
R1# traceroute 192.168.1.1

How to go back to previous command level: (From Global Configuration to privileged EXEC or User  mode):
1.       You can use command “Exit” or “end” for exiting the current EXEC mode, but if you want to go back to privileged EXEC  Mode from any mode simple hit the “Ctrl+Z” from keyboard.




In this article I have combine some of common and basic commands, if you think that there are some basic/important commands are missing here then please comment & I will update it accordingly. Thank you for reading it.


Cisco Static Routing Lab on GNS3 | Static Routes with GNS3

How to configure the static routes on GNS3

 Static routing is a core technology that any network engineer must understand.  With static Routing you can configure your network without using any dynamic routing protocol like RIP, OSPF etc. Commonly static routes are used for floating routes and a default route. A well designed network should have very few static routes because when you configure a static routes and in case of network changes, you’ll then potentially need to reassess and reconfigure the static route to ensure network connectivity.
With static routes, for successful IP communication it is necessarily you configure bi-directional static routes on each router. Consider the following figure, suppose you want to access R3 from R1, in such case you need two static routes one from R1 to R3 and other R3 to R1.
Static routing configuration is very simple and easy, you just need to advertise the remote network with defining the next hope address. Syntax of static route Cisco command is as under:
Router(config)#ip route <destination network> <mask> <next hope address>
Learn more Basic Cisco commands from here.


In above Gns3 lab you  have three routers on which we will configure routing using static routes. All required configuration are as following, you all also download the full configurations of these routers from links which are given under the configuration of each router.


R1 Configuration:
On router R1 one we have one directly connected network (11.11.11.0/24) and two remote networks 22.22.22.0/24 &  33.33.33.0/24. For static routing you need to configure two static routes for remote network and next hope address will interface f0/0 of R2 which have the IP address 11.11.11.2. Next hope address is like a gateway and IP address of neighbor router which is connected to remote network, if you want to access R3 from R1 you will access it through next hope address 11.11.11.2. 
R1#conf t
R1(config)#interface f0/0
R1(config-if)#ip address 11.11.11.1 255.255.255.0
R1(config-if)#no shut
R1(config-if)#exit
R1(config)#ip route 22.22.22.0 255.255.255.0 11.11.11.2
R1(config)#ip route 33.33.33.0 255.255.255.0 11.11.11.2
Download R1 configuration
R2 Configuration:
On router R2 we have two directly connected network 22.22.22.0/24 &  11.11.11.0/24 and remote network 33.33.33.0/24. Therefore you need to configure the only static route for 33.33.33.0/24 with next hope address 22.22.22.2.

R2#configure terminal
R2(config)#interface f0/0
R2(config-if)#ip address 11.11.11.2 255.255.255.0
R2(config-if)#no shutdown
R2(config-if)#exit
R2(config)#interface f1/0
R2(config-if)#ip address 22.22.22.1 255.255.255.0
R2(config-if)#no shutdown
R2(config-if)#exit
R2(config)#ip route 33.33.33.0 255.255.255.0 22.22.22.2
R2(config)#exit
R3 Configuration
Remote Network=11.11.11.0/24
Directly connected networks=22.22.22.0/24 &  33.33.33.0/24
Next hope address= 22.22.22.1

R3#configure terminal
R3(config)#interface f0/0
R3(config-if)#ip address 22.22.22.2 255.255.255.0
R3(config-if)#no shutdown
R3(config-if)#exit
R3(config)#interface loopback 1
R3(config-if)#ip address 33.33.33.1 255.255.255.0
R3(config-if)#no shutdown
R3(config-if)#exit
R3(config)#ip route 11.11.11.0 255.255.255.0 22.22.22.1
R3(config)#exit

Download R3 configuration

After the successful configuration show ip route on R1 will have the following output.


Cisco CLI Password Recovery Steps How to recover the router/switch password if you forget it

How to reset password of Cisco 2600, 3600,7200 series routers

Passwords are often configured on Cisco routers for security purposes and for unauthorized access. This password can be forgotten and you may need to be reset the password to access to the router. The process for recovering a password may varies from platform to platform, but each procedure follows the following basic steps:

Configure the router to boot up without reading the configuration memory (nonvolatile RAM, or NVRAM):


If we forget to enter the privileged mode password, then we'll shut down the router and reboot! Then quickly press [Ctrl + Break] key to interrupt the boot process of the router, it will enter you into rommon mode. This can be done without a password if you are in test system mode.

In this mode set the configuration register to 0x2142, which would make the router does not read NVRAM configuration file at boot time. And then restart the router!
Command is as follows:
rommon 1> confreg 0x2142 // change the configuration register is 0x2142
rommon 3> reset // restart the route or use the command reload



Then reboot the router will go directly to the setup configuration mode, use [Ctrl + C] or answered "n",
Exit setup mode! Then we enter the global mode to reset the password privileged mode.
Command is as follows:
Router> enable // privileged mode
Router # configure terminal // enter the global mode

Router (config) #enable password 1234 // reset the password of command


Cisco Interface and Line Protocol Status description | what are Line Protocol status Down/UP means

Cisco interface status description | Description of Show IP int brief command status:




You can check the Cisco interfaces with command “show ip interface brief”. The interface and line protocol status output gives information related to the physical status of the interfaces, an example of output is as shown above in figure.

When an interface is operating properly, there is only one possible status output. Following are the all possible status of interfaces.

Interface status is up, line protocol is up:

This status shows that interface is OK with physically and configured protocol is also working fine.

Interface status is down, line protocol is down

This state indicates a physical interface problem. The interface may be administratively shut down, a situation that could cause both ends to go down. To bring an interface up, use the no shutdown command under the interface configuration mode.

Interface status is  up, line protocol is down

This state means that interface is physically up but there is some protocol mismatch, attributed to a clocking or framing problem.  To resolve this issue you need to check out your protocol/keepalive configurations.

 Interface status is administratively down, line protocol is down

This state indicates interface is shutdown by administrator by using no shutdown command under the interface configuration mode. To bring the interface up, use the no shutdown command under interface configuration mode.

Interface status is up, line protocol is up (looped)

This status shows that a loop exists in the network. This problem could be associated with an existing loopback interface.

Interface status is up, line protocol is down (disabled)


This state often indicates a hardware problem and may be associated with a service provider company problem.

Advantages of GNS3 (Network Simulator) | GNS3 Vs Packet Tracer

Benefits of Using GNS3 workbench:


GNS3 is software use for simulating different virtual devices and real devices like routers, switches etc. It uses Dynamips which is an emulation software to simulate virtual devices.

It has several advantage as compare to Packet Tracer (anther network simulator), some of main features of GNS3 are as under: 

  • Gns3 uses real IOS software to simulate the different virtual devices, so you enjoy the new features of IOS with using new IOS in GNS3. Whereas the Packet Tracer is software base simulator which only allows the limited commands which are programed. Some of new commands may not works with Packet Tracer.
  • One of key advantage of GNS3 is that you can connect the simulated device or network to real world/devices. You can review some of example here. GNS3 Cloud, GNS3 Virtualbox
  • You can take packet capture with Wireshark between devices which you are simulating in GNS3.

  • GNS3 supports devices and IOS of more vendors like Cisco, Juniper, Linux host etc. as compare to Packet Tracer.
  • The main advantage of GNS3 lies in hardware emulation, since you can connect GNS3 devices to real world therefore you can ping/telnet GNS3 router from anywhere even from over the internet. Even you can configure/control the small office network with GNS3 router without using a real router.
  • You can connect and simulate VirtualBox to GNS3 and can create some of complex network labs.
  • You can create your network diagram and can represent your network architecture easily.
  • New versions of GNS3 supports IOU devices as well.
  • You can customize virtual devices by adding different slots and Cards like real network devices. 
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