Unable to find OIDs for CPU and Memory SNMP MIBs for ISG appliance.
ISG release 2.4.7.1
Below are the OIDs which can be used to get the cpu-util and memory-util:
Name/OID: .1.3.6.1.4.1.3417.2.4.1.1.1.3.1; Value (OctetString): memory-util
Name/OID: .1.3.6.1.4.1.3417.2.4.1.1.1.3.2; Value (OctetString): cpu-util