Trying to write a search to find Firewall allows by Previous Drops
I am very new to Splunk (love it so far) and am trying to write a search with a subsearch. Basically I want to find IP addresses that were denied at our firewall and then check if they were subsequently allowed at some point. So far I have:
tag=network action=allow [search tag=network NOT action=allow | dedup src_ip | table src_ip] | top src_ip by dest_ip
I think this should be correct but before I mess with it I wanted to see if there was a better way to do this.
Thank you, and sorry for the noobish question!
You might use
latest= to make the 2 parts of your search use different spans.
Probably you should use different search parameters between main search and subsearch, because if you try to connect two auto exclusive searches you'll not have any results!
In other words with the same search (tag=network) you want to find all src_ips that have at the same time action=allow and action!=allow, not possible!
You should use different search parametrs in main search or in subsearch.
Only the src_ip from the subsearch would be passed to the search, so the action!=allow does not affect the main search.
Looks good to me. May be, in the subsearch, instead of using
NOT action=allow, using
action=deny or whatever is specific action for deny is. If the possible values of action can be other then allow and deny, you may get some false positive.
either that or try
[search tag=network action!=allow | dedup src_ip | table src_ip|format]