We currently have two 3750's stacked, acting as the core for our network. They are both WS-C3750-48P switches. My company recently purchased a WS-3750E-48TD, and they would like it added to the stack. I realize that you can stack unlike models of 3750's and that the master will push its IOS to the slave switches, if they are not immediately compatible. If I make sure that both models of switch are running a new version of their latest IOS, I should be able to stack them and still have my crypto commands (for SSH) and my layer 3 funtionality, right? Is there a way to test the compatability before I have to take down services and try to stack them, or will that just have to be ready to improvise on the spot? Thanks for the help.
There is no specific test to check the compatibility. You can add the third switch when the first two are already up and running without any issues. Please follow the procedure to add the third switch. If you would like the newer switch to be the master, then you need to bring down the entire stack. If not, there are no specific issues you need to be concerned about.