Latest Cisco 3745 IOS image For Gns3

Working 3745 IOS download for Gns3

What is IOS image? 

IOS image is software or Operating System used in most Cisco routers and  switches. IOS image support different packages like routing, switching and inter-networking etc. You can use these IOS images with GNS3. Gns3 is one of the famous network simulator and its hot feature is that it can run the real Cisco IOS image, as compare to other network simulator like packet-tracer which perform all functions base on programming. If you are beginner then learn more here: how to use or configure GNS3

Remember only the c7200 series ios images get newer IOS images.  According to Cisco all other platforms are now “end of life”, but you can used these older ios images as well with Gns3.

Gns3 3745 IOS image Details

Cisco 3700 Series are the multi-service routers provide LAN/WAN connectivity, new high-density service modules, and support for multiple advanced integration modules. You can use NM-16ESW module with this 3745 IOS, which will enable the switching functionality in GNS3. In this way you will be able to perform different switching labs with GNS3 like Vlans, inter-vlan (Router on stick), VTP (vlan trunking protocol), different multi-layer functionality etc. learn more about Layer 3 Switching vs Routing

cisco 3745 image

From here you can download Cisco 3745 IOS image for your GNS3 and perform different GNS3 labs with this IOS. Remember this IOS is only for informational, practice purposes and for GNS3 used. If you need the IOS for your real hardware then it is better to Contact Cisco for latest and best IOS for your device. Following is the details  and recommended setting of  Gns3 3745 IOS image for your GNS3 setup. This Image was tested with Gns3 1.1 and i hope this will also work fine with the latest GNS3 version as well.

IOS version =12.4.25d (Mainline)

File name: c3745-adventerprisek9-mz.124-25d.bin

Minimum RAM: 128 but alteast 256MB recommended

Best idle-PC value: 0x60aa1da0 , you can set other idle PC value as well

Here is the link from where you can download IOS for your Gns3

Download Cisco 3745 image for Gns3

Run ASA 8.4.2 on GNS3

Other IOS image on this Website:

Download 1700c IOS for GNS3 Router

Layer 3 Switching vs Routing | End the Confusion! L3 vs Router

What is difference between layer-3 Switching and Routing?

To understand the difference between L3 Switching and routing, it is better to understand basic definition of switch and router.

Remember the following in case of switch and router:

  • Switch is considered as Layer-2 device that performs circuit switch or forwarding decisions based on layer 2 table and Switch performed packet forwarding with hardware switching which is faster than a router.
  • According to basic definition of a router, it is a device which performs packet switching or Layer-3 forwarding and this layer-3 routing forwarding were typically performed in software or by means of programing algorithms. If you have clear understanding of packet vs circuit switching then you can understand this concept easily.

Layer-3 Switching vs Routing

In modern world there are most of routers those can perform Layer-3 forwarding using hardware as well. Therefore, both Layer 3 switch and Layer-3 router can perform nearly identical functions with same performance. But there are still some differences in operations of Layer-3 switches and routers as following:


  1. Layer-3 switches are enhanced for Ethernet, and are mainly used for inter-VLAN routing. These Layer-3 switches can also perform their basic Layer-2 forwarding for intra-VLAN traffic.
  2. A layer-3 Switches generally have higher number of ports as compare to routers, and are consider as a cheaper device in term of per port cast as compare to routers
  3. Routers are specially build for routing therefore they support a large number of WAN technologies as compare to Layer-3 switches, L3 switches normally do not have WAN interfaces & do not support the advance routing or WAN technologies.
  4. Layer 3 switches are frequently installed at the top of LAN in building or in campus networks. Routers are predominantly used for connecting to WAN, therefore they are deployed at core layer or in main data Center.
  5. Router perform routing lookup, by introducing fast switching and CEF, packets are also now switched on a router.Switches doesn’t support some QoS features.

Fastest Ethernet Cable | High Speed Ethernet cable | How to choose ethernet cable

What is the Fastest Ethernet Cable For Your LAN:

This article is about the review of connection speed of different Ethernet cables like fiber optics, coaxial or Twisted-pair. Although every Ethernet cables are suitable for different network scenarios, for example for internal LAN normally we use the Twisted-pair or coaxial cable. Similarly for connecting two branch offices or connecting two routers in same campus we can use optical fiber. In this article we will discuss high speed Ethernet cables. If we summaries the discussion of fastest Ethernet cables we can list up the following Ethernet cables in category of high speed Ethernet cables.

  1. Fiber optics (Multimode & single Mode)
  2. Cat 7
  3. Cat6 & Cat6e
  4. Cat5 & Cat5e

Cat3 vs cat5 vs cat6

How to choose Ethernet cable?

The Ethernet cable is used mainly in the field of telephony and computing. The cat5 cable is standard Ethernet cable, allowing data rates up to 100Mbps.The category 6 cable is of superior quality and can carry up to 7Gbps.The category 7 cable is best in terms of Ethernet. Cat7 cable has shielded twisted pairs individually and collectively to reduce parasitic phenomena related to crosstalk.  Choosing your Ethernet cable depends on different factors like bandwidth cast etc. If cast is not your problem then you may select your cable according to following rules:

  • If you want to connect your device to a router or switch in your office then a cat.5 Ethernet cableis enough.
  • For connecting the core devices like router to another router or switch to switch, optical fiber, Cat6 or cat7 is your best option.

Following are the major categories of Ethernet have also been organized by their speed:

  • Ethernet (10Mbps)
  • Fast Ethernet (100Mbps)
  • Gigabit Ethernet
  • 10 Gigabit Ethernet
  • Fiber Optic

fiber optics ethernet cable

Ethernet Speed Physical Standards

Ethernet Speed is often represented by the physical standards which are labeled by their transmission rate, signaling type, and media type. For example, 100baseT represents the following:

  • 100 represent the speed of transmission rate in Mbps.
  • Keyword Base indicates that it is a baseband transmission.
  • The last part (T) represents the physical media type (twisted-pair).

Ethernet communication is baseband, which dedicates the entire capacity of the medium to one signal or channel. In broadband, multiple signals or channels can share the same link, through the use of modulation. In following table different Ethernet standards are presented with speed and distance.

Ethernet Standard Speed Distance Cable or Media type
10BASE-T 10 Mb / s 100 meters Coaxial / Twisted pair
100BASE-TX 100 Mb / s 100 meters Coaxial / Twisted pair
100BASE-FX 100 Mb / s 412 meters2 Km Half Duplex Multi-Mode FiberFull Duplex multi-mode optical fiber
1000 Base LX 1000 Mb / s
1000 Mb / s
3 Km
Single-mode FiberMulti-Mode Fiber
1000 Base SX 1000 Mb / s
1000 Mb / s
550 meters
275 meters
Multi-mode optical fiber (50u)
multi-mode optical fiber (62.5 u)
1000 Base C
(not supported by standard industrial applications)
1000 Mb / s 25 meters Copper, 4 pairs UTP5
1000 Base T – 1000 Base TX IEEE 802.3 1000 Mb / s 100 meters Twisted pair 5e cable,
1000BASE LH 1000 Mb / s 70 km Optical fiber