Adding a Layer 3 Switch in GNS3
To add a layer 3 switch in GNS3, you need to perform the following steps:
Once you have downloaded the Cisco 3640 series IOS image, open the Preferences window by clicking the Edit and then Preferences in the GNS3 console.
In the Preferences window, select IOS routers in the left pane. Here, you will see all the added IOS router templates. To add a new IOS router template, click New as shown in the following figure.
On the New IOS router template window, select the New Image radio button.
Click Browse and navigate to the location where you have downloaded the 3640 IOS image file, and then select it.
In the IOS Image message box, click Yes to decompress the selected image, and then click Next.
On the Name and platform page, type a name such as Layer 3 Switch in the Name text box, select the This is an EtherSwitch router check box and then click Next.
On the Memory page, accept the default memory size or set the desired value, and click Next.
On the Network adapters page, select NM-16ESW from the slot 0 drop-down list and then click Next.
On the Idle-PC Finder page, click Finish and close the Preferences window.
You will see that a layer 3 switch in GNS3 console has been added. Drag it to the work view area.
Right-click layer 3 switch (ESW1) and select Start to start it.
Once it is started, select and right-click again it and select Console to open its console.
On the ESW1 console, type the following commands to verify that it works as a Layer 3 switch.
ESW1(config)#hostname Switch2
Switch2#show vlan database
The following figure shows that the preceding commands are successfully executed on the layer 3 switch that you have added in GNS3.
Source
//protechgurus.com/use-add-layer-3-switches-gns3/
In our previous article, we added the Layer 2 Switch IOS image. In this article, we will configure Layer 3 Switch IOS image. As you know, L2 Switches only transmit packets according to the MAC address table.
Layer 3 switches also use the MAC address table and additionally serve as routing.
How to Use Layer 3 Switch on GNS3
Installing L3 Switch to GNS3 is almost the same as installing a Cisco Router. To perform Switching-based operations with the simulator, you need to use the L3 Switch.
With Layer 3 Switches, you can perform the VLAN, 802.1Q Trunking, and InterVLAN Routing.
Cisco Layer 3 Switch IOS Download
First, download the Switch IOS image to your computer by clicking the button below.
IOS Download
How to Add L3 Switch in GNS3
After downloading the L3 Switch IOS image to your computer, open the network simulator, and follow the steps below.
Step 1
To add a new device, click Edit.
Step 2
From the Edit menu, click Preferences.
Step 3
In the General Preferences window, click the IOS Routers tab.
Step 4
Previously we added L2 Switch from Qemu VMs. To add L3 Switch, click the New button in the IOS Router templates window.
Step 5
In the IOS Image window, select New Image, then click Browse.
Step 6
Select the IOS you downloaded from the above button and click the Open button.
Step 7
The GNS3 program asks if you want to copy the IOS to the default image folder, click Yes.
Step 8
After adding Switch IOS, click Next to continue.
Step 9
In this step, select “This is an EthernetSwitch Router” and then click Next.
Step 10
Leave the RAM value of Layer 3 Switch as default and click Next.
Step 11
In the Network Adapters window, select the NM-16ESW interface in Slot 0 and continue to the next step.
Step 12
Click the Idle-PC Finder button to select the optimal value for your computer’s processor performance for Layer 3 Switch IOS.
Step 13
Wait while calculating the Idle-PC value.
Step 14
After determining the optimal Idle-PC value for IOS, click OK to continue.
Step 15
As you can see in the image below, the Layer 3 Switch (EtherSwitch Router) has added successfully.
Step 16
Drag and drop the Switch to the GNS3 workspace.
Step 17
Create a topology as follows and double click on L3 Switch.
Step 18
Now, to test the Switch, execute the show vlan-switch command in the CLI command interface.
Configure the switch by executing the following commands.
ESW1# conf t ESW1(config)#interface vlan 1 ESW1(config-if)#ip address 192.168.10.1 255.255.255.0 ESW1(config-if)#no shutdown ESW1(config-if)#exit ESW1(config)#infterface fastethernet0/0 ESW1(config-if)#no shutdown ESW1(config-if)#exit ESW1(config)#exit ESW1#Step 19
Configure the VPCS and then ping the VLAN1 interface to test the connection as follows.
Step 20
You can see that pinging between VPCS is successful.
Show Commands
ESW1#show running-config Building configuration... Current configuration : 2035 bytes ! version 12.4 service timestamps debug datetime msec service timestamps log datetime msec no service password-encryption no service dhcp ! hostname ESW1 ! boot-start-marker boot-end-marker ! ! no aaa new-model memory-size iomem 5 no ip routing no ip icmp rate-limit unreachable ! ! no ip cef no ip domain lookup ! ! ip auth-proxy max-nodata-conns 3 ip admission max-nodata-conns 3 ! ! vtp file nvram:vlan.dat ! ! ip tcp synwait-time 5 ! ! ! interface FastEthernet0/0 description *** Unused for Layer2 EtherSwitch *** ! interface FastEthernet0/1 description *** Unused for Layer2 EtherSwitch *** shutdown ! interface FastEthernet0/2 ! interface FastEthernet0/3 ! interface FastEthernet0/4 ! interface FastEthernet0/5 ! interface FastEthernet0/6 ! interface FastEthernet0/7 ! interface FastEthernet0/8 ! interface FastEthernet0/9 ! interface FastEthernet0/10 ! interface FastEthernet0/11 ! interface FastEthernet0/12 ! interface FastEthernet0/13 ! interface FastEthernet0/14 ! interface FastEthernet0/15 ! interface Vlan1 ip address 192.168.10.1 255.255.255.0 no ip route-cache ! no ip http server no ip http secure-server ! ip forward-protocol nd ! ! no cdp log mismatch duplex ! ! control-plane ! ! mgcp behavior g729-variants static-pt ! ! banner exec ^C *************************************************************** This is a normal Router with a SW module inside (NM-16ESW) It has been preconfigured with hard coded speed and duplex To create vlans use the command "vlan database" from exec mode After creating all desired vlans use "exit" to apply the config To view existing vlans use the command "show vlan-switch brief" Warning: You are using an old IOS image for this router. Please update the IOS to enable the "macro" command! *************************************************************** ^C ! line con 0 exec-timeout 0 0 privilege level 15 logging synchronous line aux 0 exec-timeout 0 0 privilege level 15 logging synchronous line vty 0 4 login ! ! end ESW1# ESW1#show ip int br Interface IP-Address OK? Method Status Protocol FastEthernet0/0 unassigned YES unset up up FastEthernet0/1 unassigned YES unset administratively down down FastEthernet0/2 unassigned YES unset up down FastEthernet0/3 unassigned YES unset up down FastEthernet0/4 unassigned YES unset up down FastEthernet0/5 unassigned YES unset up down FastEthernet0/6 unassigned YES unset up down FastEthernet0/7 unassigned YES unset up down FastEthernet0/8 unassigned YES unset up down FastEthernet0/9 unassigned YES unset up down FastEthernet0/10 unassigned YES unset up down FastEthernet0/11 unassigned YES unset up down FastEthernet0/12 unassigned YES unset up down FastEthernet0/13 unassigned YES unset up down FastEthernet0/14 unassigned YES unset up down FastEthernet0/15 unassigned YES unset up down Vlan1 192.168.10.1 YES manual up up ESW1# ESW1#show vlan-switch VLAN Name Status Ports ---- -------------------------------- --------- ------------------------------- 1 default active Fa0/0, Fa0/1, Fa0/2, Fa0/3 Fa0/4, Fa0/5, Fa0/6, Fa0/7 Fa0/8, Fa0/9, Fa0/10, Fa0/11 Fa0/12, Fa0/13, Fa0/14, Fa0/15 1002 fddi-default active 1003 token-ring-default active 1004 fddinet-default active 1005 trnet-default active VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2 ---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------ 1 enet 100001 1500 - - - - - 1002 1003 1002 fddi 101002 1500 - - - - - 1 1003 1003 tr 101003 1500 1005 0 - - srb 1 1002 1004 fdnet 101004 1500 - - 1 ibm - 0 0 1005 trnet 101005 1500 - - 1 ibm - 0 0GNS3 L3 Switch Configuration ⇒ Video
You can watch the video below to use Switch on GNS3 and also subscribe to our YouTube channel to support us!
Final Word
In this article, we examined the GNS3 Layer 3 Switch settings, the most popular network simulator program used to prepare for Cisco exams. Thanks for following us!
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