This is correct. Campus Manager uses portAdditionalOperStatus to obtain err-disable status on switch ports.
No, this object is not supported in any 2950 IOS image.
You can use RME's Network Show Commands feature to connect to the switches, and run show commands to give you the accurate port state. For example, you could run "show int status" on these switches, and see which ports are err-disabled.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...