You can use the ISE 2.1 CLI to configure the SNMP server information. More information on the commands here:
http://www.cisco.com/c/en/us/td/docs/security/ise/2-1/cli_ref_guide/b_ise_CLIReferenceGuide_21/b_ise_CLIReferenceGuide_21_chapter_011.html#id_19714
Information on what you can monitor is here:
http://www.cisco.com/c/en/us/td/docs/security/ise/2-1/admin_guide/b_ise_admin_guide_21/b_ise_admin_guide_20_chapter_011000.html#id_17078
I checked and could not find a location where this can be done on the GUI.