152-4.m11 is widely considered the before Cisco began aggressively pushing IOS XE and ASR/ISR platforms.
That said, in the network engineering learning community, discussing is common, but copying or sharing them without rights is a violation of copyright.
(Not recommended for new deployments)
If you’ve "found" a copy of this file and want to verify its integrity, here is the official metadata from the Cisco Software Central Description: Advanced Enterprise Services Release Date: October 17, 2016 File Size: 53.58 MB (56,187,628 bytes) Minimum Memory: 512 MB DRAM / 64 MB Flash MD5 Checksum: cee15ae61eda8e10f983390cd0c829fe Why This Image is "Hot" for Labs Modern Feature Set:
Requires a minimum of 512 MB DRAM and 64 MB Flash memory to operate correctly.
The Cisco IOS image is a cornerstone for network engineers, particularly those utilizing the Cisco 7200 Series Router in virtualized lab environments. Released on October 17, 2016, this "Advanced Enterprise Services" image is often the preferred choice for CCNA and CCNP candidates due to its comprehensive feature set and compatibility with emulation software. Technical Overview and Specifications
JOY TO INSTALL