Hello @Johnny
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Two NICs are required if you plan to retain the IP addresses of the source machines on failover and want to fail back to on-premises later. One NIC is connected to source machines, and the other NIC is used for Azure connectivity.
If you want to add an additional NIC to the configuration server, add it before you register the server in the vault. Adding additional adapters isn't supported after registration.
Reference link - https://video2.skills-academy.com/en-us/azure/site-recovery/vmware-azure-deploy-configuration-server#add-an-additional-adapter
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