Thanks, but it is still getting error as below. But, when I execute logstash, I am still getting like your output.
Elasticsearch is not showing log from this firewall.
[2018-05-04T14:11:05,745][WARN ][logstash.outputs.elasticsearch] Could not index event to Elasticsearch. {:status=>400, :action=>["index", {:_id=>nil, :_index=>"logstash-2018.05.04", :_type=>"t_nettraffic", :_routing=>nil}, 2018-05-04T06:11:05.000Z x.x.x.x %{message}], :response=>{"index"=>{"_index"=>"logstash-2018.05.04", "_type"=>"t_nettraffic", "_id"=>"AsdfwesxxERDSFWExxrfwere", "status"=>400, "error"=>{"type"=>"mapper_parsing_exception", "reason"=>"failed to parse [date]", "caused_by"=>{"type"=>"illegal_argument_exception", "reason"=>"Invalid format: "2018-05-04 06:11:05 +0000" is malformed at " 06:11:05 +0000""}}}}}