The IP base is for the Standard Multilayer Software Image (SMI) switches, and the IP services image is for the Enhanced Standard Multilayer Software Image (EMI) switches in Cisco IOS Software Release 12.2(25)SEB and later.
For the Catalyst 3750 and 3560 switches, Cisco IOS Software Release 12.2(25)SEA and earlier referred to the image that provides Layer 2+ (L2) features and basic Layer 3 routing as the Standard Multilayer Image (SMI). The image that provides full Layer 3 routing and advanced services was referred to as the EMI.
The inter VLAN routing feature is supported on both IP base or SMI and IP services or EMI image Layer 3 switches. For Layer 2-only switches, you require a Layer 3 routing device with any of the previous images.
The IP Base feature set includes advanced quality of service (QoS), rate limiting, access control lists (ACLs), and basic static and Routing Information Protocol (RIP) functions. Dynamic IP routing protocols (Open Shortest Path First (OSPF), BGPv4, Enhanced Interior Gateway Routing Protocol (EIGRP)) are available only on the IP services image.
The IP Services image provides a richer set of enterprise-class features, which includes advanced hardware-based IP unicast and IP Multicast routing. Support for IPv6 Layer 3 switching in hardware is also available with the addition of the Advanced IP Services license to either the IP Base or the IP Services images. Both the IP base Image and the IP services image allow for Layer 3 and Layer 4 lookups for QoS and security.