Hello All, I was hoping someone could help me, I have three WS-C3750-48TS-E switches that I have just received from Ebay, I wish to upgrade the ISO to  12.2.55-SE12   MD   they are currently on a mixture of  12.2(55)SE7  C3750-IPSERVICESK9-M and 12.2(37)SE  C3750-ADVIPSERVICESK   The only options I can see for  12.2.55-SE12   MD are IPBase and Universal I can not find IPSERVICE, I need to retain full layer3 functions as I am using these devices to study for CCNP R&S. Am i correct in thinking that universal has all functions? if so why are my images IPservice and not Universal, and would i lost functions should i upgrade to the c3750e-universalk9-mz.122-55.SE12.bin   I would really appreciate any help anyone could provide on this, I obviously have a lot to learn about how the IOS structures work.   many thanks in advance ... View more