Splunk System Requirements

Mandatory

  • Splunk Enterprise >7.1.0
  • Splunk Enterprise Security >5.1.0

Review size of lookups in memory

Splunk utilizes a default maximum size of in memory lookup tables that can be exceeded when large numbers of CIDR assets are tracked in enterprise security. If the size is exceeded a user error will appear to the effect of CIDR match lookup can not used indexed lookups. Should the impact the environment review the size of the enterprise security lookup assets_by_cdr.csv and increase the value limits.conf/[lookup]/max_memtable_bytes to 125% of the size of this file in bytes and apply the change to both the ES Search Head and the indexer tier.

Optional - Splunk Stream

To use Splunk Stream to discovery DHCP subnets the following patch must be applied

$SPLUNK_HOME/apps/Splunk_TA_stream/local/props.conf
[stream:dhcp]
FIELDALIAS-lease_scope = subnetmask AS lease_scope