Discovery failed with exceptions: java.lang.IllegalArgumentException: Missing required parameter ip_addressIssue <!-- div.margin{ padding: 10px 40px 40px 30px; } table.tocTable{ border: 1px solid; border-color:#E0E0E0; background-color: rgb(245, 245, 245); padding-top: .6em; padding-bottom: .6em; padding-left: .9em; padding-right: .6em; } table.noteTable{ border:1px solid; border-color:#E0E0E0; background-color: rgb(245, 245, 245); width: 100%; border-spacing:2; } table.internaltable { white-space:nowrap; text-align:left; border-width: 1px; border-collapse: collapse; font-size:14px; width: 85%; } table.internaltable th { border-width: 1px; padding: 5px; border-style: solid; border-color: rgb(245, 245, 245); background-color: rgb(245, 245, 245); } table.internaltable td { border-width: 1px; padding: 5px; border-style: solid; border-color: #E0E0E0; color: #000000; } .title { color: #D1232B; font-weight:normal; font-size:28px; } h1{ color: #D1232B; font-weight:normal; font-size:21px; margin-bottom:-5px } h2{ color: #646464; font-weight:bold; font-size:18px; } h3{ color: #000000; font-weight:BOLD; font-size:16px; text-decoration:underline; } h4{ color: #646464; font-weight:BOLD; font-size:15px; text-decoration:; } h5{ color: #000000; font-weight:BOLD; font-size:13px; text-decoration:; } h6{ color: #000000; font-weight:BOLD; font-size:14px; text-decoration:; } ul{ list-style: disc outside none; margin-left: 0; } li { padding-left: 1em; } --> Symptoms There are Java exceptions in discovery logs for Network devices(Routers and switches). java.lang.IllegalArgumentException: Missing required parameterip_addressat com.service_now.mid.probe.shazzam.scanners.APortScanner.getParamAsIP(APortScanner.java:208)at com.service_now.mid.probe.shazzam.scanners.APortScanner.init(APortScanner.java:56)at com.service_now.mid.probe.shazzam.scanners.AUDPPortScanner.init(AUDPPortScanner.java:35)at com.service_now.mid.probe.shazzam.scanners.DNS.init(DNS.java:63)at com.service_now.mid.probe.DNS.addScanners(DNS.java:140)at com.service_now.mid.probe.DNS.processChunk(DNS.java:114)at com.service_now.mid.probe.ShazzamBase.syncProcessChunk(ShazzamBase.java:71)at com.service_now.mid.probe.DNS.probe(DNS.java:90)at com.service_now.mid.probe.AProbe.process(AProbe.java:84)at com.service_now.mid.queue_worker.AWorker.runWorker(AWorker.java:125)at com.service_now.mid.queue_worker.AWorkerThread.run(AWorkerThread.java:20)at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)at java.lang.Thread.run(Thread.java:748) Release Jakarta and Kingston. Cause The cause of this problem is both sensors and patterns enabled at the same time. Either of the one should be used, but not both. There is a DNS probe in discovery which is causing Java exceptions.This probe is for resolving DNS names of IPs.This would get triggered twice, one for SMMP Identity - Multiprobe and once again for Horizontal Pattern probe.When it gets triggered with SMMP Identity - Multiprobe, proper IP Addresses are being sent to DNS probe and it is processing good. No error here.When it gets triggered with Horizontal Pattern probe, "null" parameter is being sent instead of IP Address. And this activity seems to be redundant. This is because, there are both Probes and Sensors, Patterns enabled for discovery. Resolution Identify which classification is triggered for the discovery. It should be either "Standard Network Router" or "Standard Network Switch".Open the classifier. (Navigate to Discovery Definition -> CI Classification -> All and search for respective classifier).Under "Triggers Probes" section, you can remove "Horizontal Pattern".Re-run the discovery and it should go good now without errors. Additional Information You can contact Customer Support if you have any questions performing the above steps.