During the installation of the IFS ingress in 25R1 release update the following error was encountered

Error: Kubernetes cluster unreachable: Get "https://xxx-xxx.nn35x032ja3upffgyg4pykxrbb.zx.internal.cloudapp.net:16443/version": dial tcp: lookup xxx-xxx-mw01.nn35x032ja3upffgyg4pykxrbb.zx.internal.cloudapp.net: no such host

The hostname xxx-xxx-mw01.nn35x032ja3upffgyg4pykxrbb.zx.internal.cloudapp.net could not be resolved to an IP address from the management server causing network communication failure with the Kubernetes API server.

Resolution Steps:

Run the following powershell command on the management server to test connectivity:

Test-NetConnection -ComputerName xxx-xxx-mw01.nn35x032ja3upffgyg4pykxrbb.zx.internal.cloudapp.net -Port 16443

If this test fails log in to the MW server run

nslookup XXX-XXX-mw01.nn35x032ja3upffgyg4pykxrbb.zx.internal.cloudapp.net

Note the IP address returned and add Host Entry on Management Server

Re-test connectivity using Test-NetConnection. If it resolves without issues from the management server the ingress command will run successfully.