When you install vSphere with Tanzu version 7.0 Update 1c or upgrade the Supervisor Cluster from version 7.0 Update 1 to version 7.0 Update 1c, the networking topology is upgraded from a single tier-1 gateway topology to a topology that has a tier-1 gateway for each namespace within the Supervisor Cluster.
You can troubleshoot problems that you might encounter during the upgrade.