Explanation
If you have Cisco SD-Access implemented and DNA Center becomes unreachable then the wired and wireless network will continue to forward packets as usual. There will be no impact to network performance or behavior. Yes you will be able to SSH / telnet / console into switches and wireless network infrastructure as usual. For the period DNA Center is unreachable, Assurance data will be lost, and you will not be able to make configuration changes to the Cisco SD-Access network.