CA Spectrum Discovery Console models the NetScaler device as pingable. The device has responded to an ICMP ping request, but not to a SNMP request.
The Citrix NetScaler community string was configured to support to snmpwalk, sapwalk2, snmpgetnext, but not to snmpget command. CA Spectrum performs the snmpget to retrieve data from a remote host/device to model it.
snmpwalk -v2c -c <community> <IP Address> system | head
SNMPv2-MIB::sysDescr.0 = STRING: NetScaler NS11.1: Build 47.14.nc, Date: Jun 28 2016, 18:10:20
SNMPv2-MIB::sysObjectID.0 = OID: SNMPv2-SMI::enterprises.5951.1
DISMAN-EVENT-MIB::sysUpTimeInstance = Timeticks: (874287150) 101 days, 4:34:31.50
SNMPv2-MIB::sysContact.0 = STRING: WebMaster (default)
SNMPv2-MIB::sysName.0 = STRING: NetScaler
SNMPv2-MIB::sysLocation.0 = STRING: POP (default)
SNMPv2-MIB::sysServices.0 = INTEGER: 72
snmpget -v2c -c <community> <IP Address> sysObjectID.0
Timeout: No Response from <IP Address>.
snmpget -v2c -c <community> <IP Address> sysDescr.0
Timeout: No Response from <IP Address>.
Configure the Citrix NetScaler community string on the device to support snmpget command.