Yes, Its little bit tricky when you are setting DSN connection - Always follow the below stated conventions
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•Convert all upper case letters to lower case.
•Replace hyphens with underscore.
•Add the letter “i” as a prefix to the instance name, if the host name starts with a number.
•Append the letters "_uccx" to the instance name.
For example, if the host name is "802UCCX-Ha-Node1", then you should enter "i802uccx_ha_node1_uccx” in the server name field.
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There is a interesting post on this
https://supportforums.cisco.com/message/3266657#3266657
Regards
Anuj