With our sample device, Cisco 880, the IOS can be seen at the site directory: Download Home / Routers / Branch Routers / 800 series routers / c881 Integrated Services Router / IOS Software / 15.4.3M10(MD) Figure 2: show version command gives us the IOS version and model of the router. Figure 3: Directory of IOS for download. After acquiring. Cisco IOS on UNIX (IOU) is a fully working version of IOS that runs as a user mode UNIX/LINUX platform. IOU is built as an image and runs just like any other program. Layer 2 and layer 3 IOU images are available for switching and routing respectively. Cisco IOS on UNIX is aimed for internal uses only (Cisco employees). Distribution of IOU. The Cisco 3750-X provides backwards compatibility with StackWise technology in other 3750 versions. Note, however, that performance is degraded to StackWise data rates of 32Gbps. The 3750 V2 supports the 3750 (V1) and the 3750-E.
Here I am listing all the working versions of Cisco IOS which I have tested with the latest version of GNS3.
Update as on 14th May 2018 –
All the IOS, IOU, Nexus and other images has been updated, checked and verified with latest GNS3 & GSN3 VM. Download here – https://i.srijit.com/gns3images
Feel free to download them and use them for your Cisco certifications studies.
Old ones are kept intact for your reference-
- 1700 – http://i.srijit.com/CiscoIOS-GNS3
- 2600 – http://i.srijit.com/CiscoIOS-GNS3
- 2691 – http://i.srijit.com/CiscoIOS-GNS3
- 3640 – http://i.srijit.com/CiscoIOS-GNS3
- 3660 – http://i.srijit.com/CiscoIOS-GNS3
- 3725 – http://i.srijit.com/CiscoIOS-GNS3
- 3745 – http://i.srijit.com/CiscoIOS-GNS3
- 7200 (v15) – http://i.srijit.com/CiscoIOS-GNS3
- 7200p (v15) –http://i.srijit.com/CiscoIOS-GNS3
Mirror Links:
1. http://bit.ly/CiscoIOSGNS3
2. http://i.srijit.com/CiscoIOS-GNS3-1
If you face any problem setting it up with GNS3 drop me a message and I will get back to you asap.
GNS3 is an open source (GNU GPL) software that simulates complex networks while being as close as possible from the way real networks perform, all of this without having dedicated network hardware such as routers and switches.
GNS3 provides an intuitive graphical user interface to design and configure virtual networks, it runs on traditional PC hardware and may be used on multiple operating systems, including Windows, Linux, and Mac OS X.
In order to provide complete and accurate simulations, GNS3 actually uses the following emulators to run the very same operating systems as in real networks:
- Dynamips, the well known Cisco IOS emulator.
- VirtualBox, runs desktop and server operating systems as well as Juniper JunOS.
- QEMU, a generic open source machine emulator, it runs Cisco ASA, PIX and IPS.
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.
7 easy steps for upgrading Cisco IOS
1 Steps total
Step 1: Upgrading Cisco IOS
1. Verify Current IOS Version
After you login, go to enable mode, by entering the enable password. This example uses two cisco catalyst 3750 switches configured in stack mode as shown below. So, while upgrading you should upgrade the image on both the flash cards.
# show switch
Switch/Stack Mac Address : 0012.abcd.1234
H/W Current
Switch# Role Mac Address Priority Version State
----------------------------------------------------------
*1 Master 0012.abcd.1234 10 0 Ready
2 Member 0012.abcd.2345 1 0 Ready
If you have only one cisco catalyst switch (non stack mode), follow all the steps mentioned in this document, but you’ll be doing it only on one flash card.
First, verify the content of the flash cards, using “dir flash1:” command.
# dir flash1:
c3750-ipbasek9-mz.122-35.SE5.bin
# dir flash2:
c3750-ipbasek9-mz.122-35.SE5.bin
As you see above, both the flash cards contains the current IOS image file, which is version “122.35.SE5″
Verify what version of IOS image your switch is currently running. Most likely this will be same as the current IOS image file that you see in your flash card. As you see below, it is using “12.3(35)SE5″
# show ver
Switch Ports Model SW Version SW Image
------ ----- ----- ---------- ----------
* 1 24 WS-C3750G-24T 12.2(35)SE5 C3750-IPBASEK9-M
2 24 WS-C3750G-24T 12.2(35)SE5 C3750-IPBASEK9-M
2. Download Latest IOS Image from Cisco Website
Download the latest IOS image for your cisco website
Go to cisco.com -> IOS Software -> Select your Siwtch (for example: Cisco Catalyst Switch 3750G-24T) -> Click on “Download IP BASE” -> Select the latest version that you want to download (for example: 12-2.55.SE1).
While you are on this download page, copy/paste the MD5 given to your system. After we download the IOS image and move it to the switch, we’ll verify the MD5 checksum before installing the image.
3. Delete Old IOS Software Image from Flash
Since we’ll be downloading the new ISO image and moving it to the flash card, we need some space. So, delete the current old image from the flash card.
# delete /f /r flash1:c3750-ipbase-mz.122.35-35.SE5
# delete /f /r flash2:c3750-ipbase-mz.122-35.SE5
# dir flash1:
# dir flash2:
In the above delete command, /f stands for force, and /r stands for recurssive.
On a side note, you should be using some software to monitor your switch status. If you are not doing it install Nagios, and monitor your switches.
4. Copy the IOS image to Cisco Switch
To transfer the IOS image from your laptop to Cisco Switch, you should run a TFTPserver on your laptop (or on the system where you’ve downloaded the IOS image).
If you are running a TFTPserver on your laptop, and connected to the switch using a console cable, assign a ip-address to your laptop, and put your laptop on the same network as the switch.
Copy the ISO image to the flash as shown below using the “copy command”. This will ask you to enter the address of the remote host (which is your laptop in this case), and the source filename that needs to be transferred (which is the ISO image you downloaded from cisco website).
# copy tftp flash1
>Address or name of remote host? 192.168.1.10
>source filename? c3750-ipbasek9-mz-122-55.SE1.bin
>Destination filename? c3750-ipbasek9-mz-122-55.SE1.bin
Once you’ve copied it, make sure the file is there on the flash card.
# dir flash1:
c3750-ipbasek9-mz-122-55.SE1.bin
Just to make sure nothing went wrong during the copy, do a MD5 check-sum on this, and compare with the MD5 that you noted down from cisco website while downloading the IOS image. To create MD5 checksum of a file in Cisco catalyst switch, use the “verify” command as shown below.
# verify /md5 flash1:c3750-ipbasek9-mz-122-55.SE1.bin
If you are running two switches in stack configuration, do the same on the second flash card.
# copy tftp flash2:
# dir flash2:
# verify /md5 flash2:c3750-ipbasek9-mz-122-55.SE1.bin
5. Modify Switch Boot path-list
Now it is time to tell switch cisco to use the new ISO image to boot from. Before changing the boot information, verify the current configuration, and change it using the “boot system” command as shown below.
# show boot
# config t
# boot system switch all flash:c3750-ipbasek9-mz-122-55.SE1.bin
6. Save Config and Restart the Switch
Verify the current boot information, save the current configuration, and reboot the cisco switch as shown below.
# show boot
# write mem
# reload
7. Final Verification after IOS Upgrade
Cisco 3750 Ios Image Download For Gns3
Finally verify the current IOS version of the switch, after the upgrade, it should display the new version as shown below.
# show ver
Switch Ports Model SW Version SW Image
------ ----- ----- ---------- ----------
* 1 24 WS-C3750G-24T 12.2(55)SE1 C3750-IPBASEK9-M
2 24 WS-C3750G-24T 12.2(55)SE1 C3750-IPBASEK9-M
Make sure to verify your interface and vlan status, to make sure everything is running properly without any issues.
References
- Upgrading Cisco IOS