Why does error "Empty csv lookup file (contains only header) for table asset_lookup_by cidr" appear on indexers when using the Splunk App for Unix and Linux?

[TWiseOne]

HI,

I recently deployed Splunk Enterprise Security 4.5 into a Search Head Cluster and whenever I use the Splunk App for Unix and Linux, I am getting the below error from all indexers:

[PROD-XX-X] Empty csv lookup file (contains only a header) for table 'asset_lookup_by_cidr': /opt/splunk/var/run/searchpeers/57E9834B-43B4-41D0-A3BD-042A352C4C79-1480672942/apps/SA-IdentityManagement/lookups/assets_by_cidr.csv

After investigations using http://docs.splunk.com/Documentation/ES/4.5.0/User/AssetandIdentityMerging the assetsbycidr.csv does not get updated as the search that populates it returns no values. It looks like it is meant to be empty, at least on this system, due to missing cidr information on the asset list.

How can I stop this error appearing whenever I use the Splunk App for Unix and Linux on a SH cluster?

Thanks

[TWiseOne · Accepted solution]

In order to fix this I added a single line of dummy information to the assets.csv file which had the CIDR block at the end of the IP address. I updated the file on the Deployer and pushed it out to the SHC, did a rolling restart and now the error has disappeared.