<h2>Not able to discover Palo Alto firewall devices via schedules or quick discovery some times.</h2><br/><div style="overflow-x:auto"><article><div ><h3 >Issue </h3><section><p style="padding-left: 40px;">Not able to discover Palo Alto firewall devices via schedules or quick discovery some times.</p> <ul style="list-style-position: inside;"><li>Credentials are validated successfully</li><li>Device's are getting discovered intermittently</li></ul></section></div><div ><h3 >Cause</h3><section><ol style="list-style-position: inside;"><li>SNMP uses UDP, which does not create a virtual connection to the target host as TCP, and no reply may be given if a credential is not correct or authorized depending on the version used. A timeout can be seen in the discovery log when an invalid credential is used.</li><li>Error ind discovery logs "SNMP probe timed out. Target is either unreachable or there are no valid credentials for it"</li><li>Couple of reasons for a timeout are: <ol style="list-style-position: inside;"><li>The credential is not valid --- tested credentials(Validated successfully)</li><li>The network or target server is too busy and does not return the OIDs within the timeout.</li></ol> </li></ol></section></div><div ><h3 >Resolution</h3><section><ol style="list-style-position: inside;"><li>Add the below probe parameter for SNMP-Classify probe, <ul style="list-style-position: inside;"><li>"request_interval"</li></ul> </li><li>Add "request_interval" probe parameter and set the property to 1000ms. Default is 400ms.</li><li>This will fix intermittent discovery issue of Palo Alto firewall devices.</li></ol></section></div></article></div>