If you are using Splunk version 6.2, "Deployment Monitor" App (comes default with installation/upgrade to 6.2) given forwarder information. If you are using pre-6.2 release in your perf environment, then install 6.2 version on your test environment, goto "Deployment Monitor" app and get the search queries populating the forwarder information in the dashboard.
Also there is app called "Data Onboarding" https://apps.splunk.com/app/1769/#/overview , install and see if you can find any useful information for you. From the dashboard you can get the search query and then you can customize and use it accordingly.
E.g: below query from "Data Onboarding" app dashboard give information about all forwarders
index="_internal" source="metrics.lo" group=tcpin_connections | eval sourceHost=if(isnull(hostname), sourceHost,hostname) | eval connectionType=case(fwdType=="uf","universal forwarder", fwdType=="lwf", "lightweight forwarder",fwdType=="full", "heavy forwarder", connectionType=="cooked" or connectionType=="cookedSSL","Splunk forwarder", connectionType=="raw" or connectionType=="rawSSL","syslog")| eval build=if(isnull(build),"n/a",build) | eval version=if(isnull(version),"pre 4.2",version) | eval guid=if(isnull(guid),sourceHost,guid) | eval os=if(isnull(os),"n/a",os)| eval arch=if(isnull(arch),"n/a",arch) | fields connectionType sourceIp sourceHost sourcePort destPort kb tcp_eps tcp_Kprocessed tcp_KBps splunk_server build version os arch guid
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