GNS3 is an excellent alternative or complementary tool to real labs for network engineers, administrators and people studying for certifications such as Cisco CCNA, CCNP andCCIE as well as Juniper JNCIA, JNCIS and JNCIE. Virtual Labs; Forums. How to Install a Cisco (IOS) Router On GNS3 VM. Parvez Ahmed. July 24, 2017 Views: 14826. (CISCO IOS) image and emulate the router.

Cisco IOS images for Dynamips GNS3 offers multiple ways to emulate IOS. For older images, we use and maintain Dynamips; an emulator dedicated to emulate some Cisco hardware. Dynamips can run unmodified IOS images. In the new GNS3 1.4, there is a way to run a second category of switches and routers. These are classified as Routing and Switching virtual machines (or R+Svms) for short.

What are the differences? Here are the major differences: • IOS images are usually run in Dynamips however R+Svms are housed in a virtual machine. • IOS images are lower in cpu and memory so you can fit more of them in one topology.

• R+Svms are all vendor Routing and Switching images that are larger in size but c an be imported into GNS3 for real world network emulation. Only the c7200 series get newer IOS 15 images. All other platforms are now end-of-life and only support IOS 12.4. Please note that the IOSv appliance is based on IOS 15 and there are IOU (IOS on UNIX) images with IOS 15.

You will find the technology train images to contain the newest features but it may also contain the most bugs. We recommend Mainline over Technology train if you are interested on stability without the need of new features.Please see for more information. The minimum RAM is the amount of memory needed for IOS to work at maximum capacity with most feature configured and activated. From experience you can usually use a bit less RAM just fine. We really recommend using c3640, c3660, c3725, c3745 and c7200 IOS images listed below, they have proven to be the most stable in GNS3 provided you use the right amount of RAM and Idle-PC value. This settings will help Dynamips to consume less CPU.

It’s specific to each different IOS image. 1700s have 1 FastEthernet fixed port (C1700-MB-1ETH) on its motherboard, 2 subslots for WICs (maximum of 2 Ethernet ports or 4 serial ports), and no Network Module slots. Note that interfaces do not use a slot designation (e.g. “f0”) File name: c1700-adventerprisek9-mz.124-25d.bin MD5: 3ed8d105a716 Minimum RAM: 128MB Proposed idle-PC value: 0x80358a60 File name: c1700-adventerprisek9-mz.124-15.T14.bin MD5: 351190de8764263e85a2b50718f394fd Minimum RAM: 160MB Proposed idle-PC value: 0x824a4dc4 2600s have one or two Ethernet or FastEthernet interfaces on its motherboard, 3 subslots for WICs (maximum of 6 serial ports) and 1 Network Module slot (maximum of 4 Ethernet ports or 16 FastEthernet ports).

File name: c2600-adventerprisek9-mz.124-25d.bin MD5: 8eca1f6fe57dfb3c3cf3568c0e475853 Minimum RAM: 128MB Proposed idle-PC value: 0x80519c48 File name: c2600-adventerprisek9-mz.124-15.T14.bin MD5: 12b8548b23e2ec593652ae9310ac797f Minimum RAM: 256MB Proposed idle-PC value: 0x8027ec88 The c3620 supports up to 2 Network Modules (maximum of 8 Ethernet ports, 32 FastEthernet ports or 8 serial ports). Note that tt shouldn’t be used since the latest available IOS image is very old. File name: c3620-a3jk8s-mz.122-26c.bin MD5: dd34b958ad362ef54ba48b187f4c97b4 Minimum RAM: 64MB Proposed idle-PC value: 0x603a8bac The c3640 supports up to 4 Network Modules (maximum of 16 Ethernet ports, 32 FastEthernet ports or 16 serial ports).

File name: c3640-a3js-mz.124-25d.bin MD5: db9f63ca1b46d18fb835496bfffe608a Minimum RAM: 128MB Proposed idle-PC value: 0x6050b114 The c3660 has 2 FastEthernet fixed ports (Leopard-2FE) and supports up to 6 Network Modules (maximum of 24 Ethernet ports, 32 FastEthernet ports or 24 serial ports). File name: c3660-a3jk9s-mz.124-25d.bin MD5: 4ac7e947f13c189d746149dc74992890 Minimum RAM: 192MB Proposed idle-PC value: 0x606071f8 File name: c3660-a3jk9s-mz.124-15.T14.bin MD5: 39950b7a563aa60409f1e6 Minimum RAM: 256MB Proposed idle-PC value: 0x6076e0b4 The c2691 has 2 FastEthernet interfaces its motherboard (GT96100-FE), 3 subslots for WICs (maximum of 6 serial ports) and 1 Network Module slot (maximum of 16 FastEthernet ports or 4 serial ports). File name: c2691-adventerprisek9-mz.124-25d.bin MD5: a8e1f585488d6221ce42e5 Minimum RAM: 192MB Proposed idle-PC value: 0x60a48cb8 File name: c2691-adventerprisek9-mz.124-15.T14.bin MD5: 913ad09204e36d2dfcf52d Minimum RAM: 256MB Prop osed idle-PC value: 0x60bcf9f8 The c3725 has 2 FastEthernet interfaces on its motherboard (GT96100-FE), 3 subslots for WICs (maximum of 6 serial ports) and 2 Network Module slots (maximum of 32 FastEthernet ports or 8 serial ports).