Troubleshooting Aruba IAP not joining the Cluster.

Real Life Case Study Problem Statement: An Aruba IAP 205 not joining a cluster of 5   Aruba  IAP 103. Scenario 1 : This is a LAN only setup with no internet connection. 1.5 IAP were deployed in the L2 network having OS verion: 6.4.2.3-4.1.1.4_49446. Everything working fine. IAP 205 with OS: 6.4.2.6-4.1.1.6_50009 was [...]