most networking design classes are vendor-specific.
However, training providers such as Global Knowledge offer networking foundation courses that are generally vendor independent. Check the link below and scroll down to the section ´Networking Foundation´:
I think a lot of the concepts within the CCDA/P content are quite relevant to non-Cisco based networks. It is certainly worth going thru the course content for these certifications since you will very likely be meeting Cisco equipment if you are planning to designing any IP network.
Just skip the sales talk and focus on the concepts...