What is the maximum version of IOS that can be upgraded to for Cisco 2621? Mine is 12 2 8

Go to the official website to find the model you want, and then go to the Internet to search, if that doesn't work, don't learn Cisco.

I can give as many points as you want.

The switch you use in gns doesn't do well with switch emulation, it doesn't work with this In reality, 2960 is supported, 3560 is not supported.

The general way to upgrade your router is to use your own machine as a TFTP server.

Connect the computer to the intranet port of the router, use the consol cable to enter the router, and ping each other on the computer and the router.

3。Once you've done that, it's very simple, first check the router's flahs space (show flash).

4。If you have enough space, upload iOS.

copy tftp flash

Then he will ask you for the name you saved, the address of the TFTP server, which is the address of your own computer.

5。Of course, you have to set the root directory of iOS on the TFTP software first, and then put the new iOS you have downloaded from the Internet.

6。After the upload is successful, enter the cong t mode and then I remember that it is system boot followed by flash: ios name should be like this, can you? Take a look.

7。Be sure to write

8.Reboot, OK

Check through Cisco** that the minimum iOS version required by your board, if it is supported, it may be that there is a problem with your board, upgrade the ios command copy tftp flash

Install the TFTP server software.

Privileged mode.

copy tftp flash

ip address or name of remote host [?Server address).

name of file to copy?c3640-is-mz 120-7 This file should be stored in the TFTP software directory of the TFTP server).

copy c3640-is-mz_120-7_ from into flash memory? [confirm]

flash is filled to capacity.

erasure is needed before flash may be written.

erase flash before writing? [confirm]

eeeeeeeeeeeeeeee...

loading from :!

Do you want to ask which series of products to look at on iOS.

Now the switch product system has been updated to the IOS-XE system, and the version number of the router and switch has been updated to the version;

The modular multi-layer switching 4500x 6500 series product line has also been updated to the IOS-XE system;

The difference between IOS-XE and traditional iOS: The new XE system integrates various latest iOS features compared with the old IOS system, and the configuration method is not much different.

Upstairs to copy a bunch of useless still didn't solve the problem of lz.

Let me tell you: you don't need to re-purchase a license to upgrade iOS, and after upgrading iOS, your previously purchased license will be automatically activated, so you don't need to worry.

How do we deal with the big changes - Standalone Images iOS 15 is a separate package for the hardware platform you are using, and now Flash is very large and cheap, so there is no need to install different versions of iOS images for different advanced features. One mirror, all functions integrated. Authorization and Cisco License Manager noted that iOS 15 implements the way in which authorization enables the advanced feature set.

That means registering an authorization code for each iOS image with advanced IP features enabled and activating those features. The authorization method is similar to the ASA authorization method. You will need to purchase an authorization and receive a written document with a PAK code, register with Cisco** to get an activation code, and enter it into your router.

If you need an advanced feature set, there is also a purchase license and activate it on the router.

Cisco devices become more difficult to manage Ciscoios AuthorizationCisco Authorization Manager.

If you are a large company, it is time to deploy Cisco Authorization Manager so that you can manage the entitlements on all your devices. This allows you to manage and transfer licenses between actual devices.

Software Activation Configuration Guide.

Didn't see the detailed configuration on the blog, Cisco

The documentation has always been very clear and straightforward and Cisco has provided the best documentation. You can find more softwareactivation configuration guides

It's time to go and learn what you should know.

Can it solve your problem?

Cisco 3750 switch IOS does not support OSPF, the -S model you purchased is not right, it can only be supported if it is -e, and this cannot be upgraded by yourself. You need to find your buyer.