I use router version 15.2(4)S5 and it working on GNS3. Follow:
R1#show con?
configuration connectedapps connection context
controllers
R1#show con
R1#
R1#show connection ?
all All Connections
elements Show Connection Elements
id ID Number
name Connection Name
port Port Number
| Output modifiers
<cr>
R1#show connection port ?
% Unrecognized command
R1#show connection port
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Thanks.