EDIT: My general question is if different versions of ios, spanning from 12 and 15, can work well in direct connection.
I am in way over my head because I went ahead and ordered a full CCIE lab without even taking my CCENT, I just really wanted something to practice on.
Here's the problem, I ordered six 2811 Routers (running on ios15), and then got three more routers to function as my backbone routers. These backbones are 2821XM, which run on ios12. That won't be a problem right? I just want them for OSPF and BGP labs.
I'm dying here because I actually paid more for the 2621XMs than I did for the 2821s: they were all refurbished, and I am learning that the refurbished market is highly illogical price-wise.
Should I bite the bullet and just buy three more 2821s to keep the ios15 uniform? I might be able to salvage the 2621XMs* for random home projects. I'm ordering from Hawaii, so returning and reshipping some heavy cheap refurbished routers isn't going to be an option.
Thanks to anyone who can help a noob out!