Best Cisco IOS for GNS3

The best IOS version to emulate everything on GNS3 is IOS 7200. With this you can do everything. Frame-Relay Switch to BGP, ISIS etc, just everything.

For switching you have to use IOU. You can't rely on Swicth Module with 3640.

I'm using Cisco IOS Software, 7200 Software (C7200-ADVENTERPRISEK9-M), Version 15.2(4)S3, RELEASE SOFTWARE (fc1) for Frame-Relay Switch Lab.

S2(config)#do show run | inc switch

frame-relay switching

IP Access list. Deny ICMP

L3-AE-IOU1(config)#do sh run
Building configuration...

Current configuration : 1967 bytes
!
version 15.1
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
service compress-config
!
hostname L3-AE-IOU1
!
boot-start-marker
boot-end-marker
!
!
!
no aaa new-model
no ip icmp rate-limit unreachable
!
ip cef
!
!
no ip domain-lookup
no ipv6 cef
ipv6 multicast rpf use-bgp
!
!
!
!
!
!
!
spanning-tree mode pvst
spanning-tree extend system-id
!
!
!
!
vlan internal allocation policy ascending
!
ip tcp synwait-time 5
!
!
!
!
!
!        
!
!
!
interface Ethernet0/0
 duplex auto
!
interface Ethernet0/1
 switchport access vlan 10
 switchport mode access
 duplex auto
!
interface Ethernet0/2
 switchport access vlan 10
 switchport mode access
 duplex auto
!
interface Ethernet0/3
 duplex auto
!
interface Ethernet1/0
 shutdown
 duplex auto
!        
interface Ethernet1/1
 shutdown
 duplex auto
!
interface Ethernet1/2
 shutdown
 duplex auto
!
interface Ethernet1/3
 shutdown
 duplex auto
!
interface Serial2/0
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial2/1
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial2/2
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial2/3
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial3/0
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial3/1
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial3/2
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial3/3
 no ip address
 shutdown
 serial restart-delay 0
!
interface Vlan1
 ip address 10.0.32.1 255.255.255.0
!
interface Vlan10
 ip address 10.0.33.1 255.255.255.0
 ip access-group 100 in
!
!
no ip http server
!
ip route 0.0.0.0 0.0.0.0 10.0.32.20
!
access-list 100 deny   icmp host 10.0.33.37 any
access-list 100 permit ip any any
!
!
!        
control-plane
!
!
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

The above config blocks PC2 from sending any Ping in the given diagram:

VLAN Routing

L3-AE-IOU1#sh run
Building configuration...

Current configuration : 1923 bytes
!
! Last configuration change at 12:42:13 UTC Wed Oct 25 2017
!
version 15.1
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
service compress-config
!
hostname L3-AE-IOU1
!
boot-start-marker
boot-end-marker
!
!
!
no aaa new-model
no ip icmp rate-limit unreachable
!
ip cef
!
!      
no ip domain-lookup
no ipv6 cef
ipv6 multicast rpf use-bgp
!
!
!
!
!
!
!
spanning-tree mode pvst
spanning-tree extend system-id
!
!
!
!
vlan internal allocation policy ascending
!
ip tcp synwait-time 5
!
!
!
!      
!
!
!
!
!
interface Ethernet0/0
 duplex auto
!
interface Ethernet0/1
 switchport access vlan 10
 switchport mode access
 duplex auto
!
interface Ethernet0/2
 switchport access vlan 10
 switchport mode access
 duplex auto
!
interface Ethernet0/3
 duplex auto
!
interface Ethernet1/0
 shutdown
 duplex auto
!
interface Ethernet1/1
 shutdown
 duplex auto
!
interface Ethernet1/2
 shutdown
 duplex auto
!
interface Ethernet1/3
 shutdown
 duplex auto
!
interface Serial2/0
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial2/1
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial2/2
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial2/3
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial3/0
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial3/1
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial3/2
 no ip address
 shutdown
 serial restart-delay 0
!
interface Serial3/3
 no ip address
 shutdown
 serial restart-delay 0
!
interface Vlan1
 ip address 10.0.32.1 255.255.255.0
!
interface Vlan10
 ip address 10.0.33.1 255.255.255.0
!
!
no ip http server
!
ip route 0.0.0.0 0.0.0.0 10.0.32.20
!
!
!
!
control-plane
!
!
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

L3-AE-IOU1#

Router Config:

/ip address

add address=10.0.32.20/24 interface=ether1 network=10.0.32.0

/ip dhcp-client

add dhcp-options=hostname,clientid disabled=no interface=ether2

/ip firewall nat

add action=masquerade chain=srcnat

/ip route

add check-gateway=ping distance=1 dst-address=10.0.33.0/24 gateway=10.0.32.1

How to connect to GNS3 from Local Windows System?

This article also tries to answer the following questions:
1. How to connect to remote topology running on GNS3 VM?
2. How to access Mikrotik Routers running inside GNS3 VM from Local System using Winbox?

=> Steps to follow:
1. Install OpenVPN Tap driver. Download and Install the OpenVPN Client.
2. Check the following:

By default the connection is showing Unplugged. See the TAP #1 in the given snap. Its up. You need an UP interface. To set the connection up, do the following:

Open Properties- Advanced and Change the following:

And you are done. Now to connect to Remote Topology running on GNS3 VM do the following shown in the snap:

And that's all.

Using a "Microsoft Loopback Adapter" also accomplishes the same thing.

Network Simulators for Windows

Above is eNSP. It allows you to simulate Huawei Devices.

Following is HP Network Simulator which simulates HP Devices:

You must install VirtualBox-5.0.16-105871-Win on Windows 7 as that only particular version works perfectly with both eNSP and HP Network Simulator. Also need to set this enviornment variable: Vbox_Install_Path=

Deleting VMNET Adapters from Windows PC

Following is the code you need to run in elevated CMD:

"C:\Program Files (x86)\VMware\VMware Workstation\vnetlib.exe" -- remove adapter vmnet2 "C:\Program Files (x86)\VMware\VMware Workstation\vnetlib.exe" -- remove adapter vmnet3 "C:\Program Files (x86)\VMware\VMware Workstation\vnetlib.exe" -- remove adapter vmnet4 "C:\Program Files (x86)\VMware\VMware Workstation\vnetlib.exe" -- remove adapter vmnet5 "C:\Program Files (x86)\VMware\VMware Workstation\vnetlib.exe" -- remove adapter vmnet6 "C:\Program Files (x86)\VMware\VMware Workstation\vnetlib.exe" -- remove adapter vmnet7 "C:\Program Files (x86)\VMware\VMware Workstation\vnetlib.exe" -- remove adapter vmnet9 "C:\Program Files (x86)\VMware\VMware Workstation\vnetlib.exe" -- remove adapter vmnet10 "C:\Program Files (x86)\VMware\VMware Workstation\vnetlib.exe" -- remove adapter vmnet11 "C:\Program Files (x86)\VMware\VMware Workstation\vnetlib.exe" -- remove adapter vmnet12 "C:\Program Files (x86)\VMware\VMware Workstation\vnetlib.exe" -- remove adapter vmnet13 "C:\Program Files (x86)\VMware\VMware Workstation\vnetlib.exe" -- remove adapter vmnet14 "C:\Program Files (x86)\VMware\VMware Workstation\vnetlib.exe" -- remove adapter vmnet15 "C:\Program Files (x86)\VMware\VMware Workstation\vnetlib.exe" -- remove adapter vmnet16 "C:\Program Files (x86)\VMware\VMware Workstation\vnetlib.exe" -- remove adapter vmnet17 "C:\Program Files (x86)\VMware\VMware Workstation\vnetlib.exe" -- remove adapter vmnet18 "C:\Program Files (x86)\VMware\VMware Workstation\vnetlib.exe" -- remove adapter vmnet19

Creating VLANS in GNS3 with MROS and Cisco

When you create VLAN in GNS3 in MROS its crucial to know what adapter model you are selecting under network interfaces. To be specific the intel e1000 adapter is capable of handling VLAN tags in hardware, thus when you select it the software will try to emulate that exact behavior. This will produce incorrect results.

Use RealTek Adapter model for all MROS emulations. It works well.

For QEMU emulated Windows XP, you must use e1000 adapter as this allows you to set VLAN in Ethernet Adapter. You will need to install the IntelPro Ethernet Adapter and its Advanced Services.

OSPF Basics - MultiArea OSPF with three Routers in GNS3

Requirement: Connect two routers on l3 using OSPF using different area ID.

Following is a snap of the current Topology:

R2 is the mediator and will make R1 and R3 communicate to each other. But R1 and R3 are in area 1 and area 2 respectively.

Following are the OSPF Configurations of three Routers:

R1:
c3725-R1(config)#do sh run | begin ospf
router ospf 1
 log-adjacency-changes
 network 1.1.1.0 0.0.0.255 area 1

R2:
c3725-R2(config)#do sh run | begin ospf
router ospf 1
 log-adjacency-changes
 redistribute connected
 network 1.1.1.0 0.0.0.255 area 1
 network 1.1.2.0 0.0.0.255 area 2
 default-information originate always

R3:
c3725-R3(config)#do sh run | begin ospf
router ospf 1
 log-adjacency-changes
 network 1.1.2.0 0.0.0.255 area 2

The above configuration produces the following routes:

R1:
c3725-R1(config)#do sh ip ro
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route

Gateway of last resort is 1.1.1.2 to network 0.0.0.0

     1.0.0.0/24 is subnetted, 1 subnets
C       1.1.1.0 is directly connected, Serial1/0
O*E2 0.0.0.0/0 [110/1] via 1.1.1.2, 00:06:15, Serial1/0

R2:
c3725-R2(config)#do sh ip ro
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     1.0.0.0/24 is subnetted, 2 subnets
C       1.1.1.0 is directly connected, Serial1/0
C       1.1.2.0 is directly connected, Serial1/1

R3:
c3725-R3(config)#do sh ip ro
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route

Gateway of last resort is 1.1.2.1 to network 0.0.0.0

     1.0.0.0/24 is subnetted, 1 subnets
C       1.1.2.0 is directly connected, Serial1/0
O*E2 0.0.0.0/0 [110/1] via 1.1.2.1, 00:06:17, Serial1/0

Fix Mouse Pointer regression on GNS3 QEMU VMs

In some VMs you will notice connecting via VNC gives a very bad mouse cursor movement experience.

You need to add the following after -nographic to fix the issue:

Add the following in place of -nographic:

-nographic -usbdevice tablet -vga std -nodefaults