Host updates fail due to DNS issues with vSphere Lifecycle Manager

Products

• VMware vSphere ESXi

Issue/Introduction

Using vSphere Lifecycle Manager, host updates fail with error: "ESX cannot resolve the DNS name of VMware vSphere Lifecycle Manager patch store. Ensure that the Lifecycle Manager server name can be resolved from ESX hosts."

Environment

• VMware vSphere 7.0 or later
• VMware vCenter Server 7.0 or later 

Cause

DNS for dl.broadcom.com is not being resolved properly. 

Resolution

• Test the resolution of dl.broadcom.com by running the below command from affected ESXi host.

  • nslookup dl.broadcom.com

• Example output:

  • Non-authoritative answer:
    dl.broadcom.com   canonical name = dl.broadcom.com
    dl.broadcom.com canonical name = dl.broadcom.com.cdn.cloudflare.net
    Name:   dl.broadcom.com.cdn.cloudflare.net
    Address: 2606:4700:7::a5
    Name:   dl.broadcom.com.cdn.cloudflare.net
    Address: 2a06:98c1:58::a5
    
    Non-authoritative answer:
    dl.broadcom.com   canonical name = dl.broadcom.com
    dl.broadcom.com canonical name = dl.broadcom.com.cdn.cloudflare.net
    Name:   dl.broadcom.com.cdn.cloudflare.net
    Address: 172.66.0.165
    Name:   dl.broadcom.com.cdn.cloudflare.net
    Address: 162.159.140.167

• If this is not the output received, there is an issue with the DNS server that should be investigated. Attempt another DNS server to confirm, or investigate the DNS server itself. 

Additional Information

Troubleshooting Steps:

1. Check DNS Configuration on ESXi: (/etc/resolve.conf)

   • Verify if the configured DNS server is reachable from the ESXi host.
   • Use network troubleshooting tools to confirm connectivity.(ping,netcat,nslookup)

2. Test vCenter FQDN Resolution from ESXi:

   • Try resolving the vCenter Fully Qualified Domain Name (FQDN) from the ESXi host.

3. If vCenter FQDN is Not Resolving but DNS is Reachable:

   • Check the DNS server for proper AAA and PTR records associated with vCenter.

4. If vCenter IP is Reachable but DNS Resolution Fails:

   • Manually add the vCenter IP address and FQDN to the ESXi host’s local hostname resolution file.(/etc/hosts)
   • Similarly, add the ESXi IP and FQDN to the vCenter’s hostname resolution file. (/etc/hosts)
   • Retry resolving the vCenter FQDN from ESXi to confirm the fix.

Goal:
Ensure that the vCenter FQDN is resolvable from ESXi, as ESXi relies on it (using port 9084) to download updates from the VMware repository (dl.broadcom.com). If the FQDN cannot be resolved, update failures and related errors may occur.