NSX native load balancer returns 502 Bad Gateway? Check the header size limits in the HTTP application profile, find the 502 in the Edge LB error and access logs, and verify pool and server-side SSL.
VMs on the same NSX segment talk on one host but not across hosts? Check TEP-to-TEP connectivity and MTU with vmkping, read tunnel BFD state in vmkernel.log and uplink events in vobd.log.
Why a Tier-0 BGP session to the ToR does not come up (VLAN ID or BGP configuration mismatch), how to check it from the NSX Edge CLI, and how to read frr.log and syslog.
Host Down or Host Disconnected in NSX? Which NSX host agent is behind it (nsx-proxy, nsx-opsagent, nsx-cfgagent, nsx-nestdb), how to check and restart it on ESX, and which logs to read.
Which vCenter or VCF certificate is failing, and which tool fixes it: an alarm-to-fix map for vCenter 7, 8 and 9, vCert vs lsdoctor, and auto-renewal.
Which vCenter file to download for an upgrade or patch (full VCSA ISO or patch-FP.iso), where it is on the Broadcom portal, and every 8.0 and 9.x build.
Why an ESXi host stops at VMware Hypervisor Recovery or No hypervisor found, and how to fix it: KB 324877, Shift+R rollback, repair install.
How a custom CA changes VCF 9 certificate operations: what Fleet Management auto-renews, what stays manual, and how new ESX hosts must be onboarded.
vCenter 8.0 U3h and VCF 9.0.2 renew VMCA Machine SSL and ESXi certificates automatically. What is covered, which thresholds apply, where vCert fits.
Renewed Machine SSL but port 3128 still shows an old cert? What vCert's LEGACY STS result means and how to move STS to MACHINE_SSL_CERT.