Hi,
Symantec_Endpoint_Protection_12.1_RU1_Part1_Installation_EN.exe contains the installation files for 12.1 RU1
Symantec_Endpoint_Protection_12.1.1_MP1_Part2_Tools_EN.exe contains the TOOLS for 12.1.1 MP1
To have the latest SEP full version, you only need the 12.1.1 MP1 part 1 installation file.
For a fresh installation, every SEP release is good and complete, you do not need to install first RU1 and then RU1 MP1 on it.
For migrations, the logic the following:
- from any to the latest RU
- from an RU to any of its own MP