This object identifies the filter group containing
information about ICMP message. This value must
match an entry in cfgFilterGroupTable whose
cfgFilterGroupType value is set to 'icmp' and must
match an entry in cfgFilterICMPGroupTable.
This object cannot be set if any of the following
objects are set:
cippfIpFilterICMPType
cippfIpFilterICMPCode.
This object is not instantiated if not applicable.