We have Cisco ACI Version 3.0(2n), running VMware 6.7 U2 | UCS-FI (B200 M4)
Cluster has vMotion network configured correctly. when we put ESXi host in maintenance mode most of the VM moved with one ping lost. but few VMs move to other ESXi-host without issue but ping stops on them. did more research on this. SSH into ESXi: each host have 6 uplink & VMware VDS being used. Found the VM pin to uplink & shut that uplink down immediately VM ping came up. So its pointing towards ACI. We detailed check UCS-FI config for allowed Vlan. Also double checked ACI-EPG configuration & static ports.
Can I have some help here?
Sounds like a stale endpoint issue. See the endpoint learning whitepaper which describes a few of the scenarios:
You should also upgrade your fabric to a release >= 3.2(2l) - from this release on they implemented some enhancements regarding endpoint-learning. Go for the newest 3.2 or 4.2 release.
Just to add, VMware 6.7 (in case you're doing VMM integration) isn't supported with APIC 3.0. You'd need to be at 3.2(2) or later.