A factory switch no longer answers SSH or its web page because its management address is gone. A serial console on the switch still responds. How should the technician get in?
Select an answer to reveal the explanation.
Short Explanation
When the network door will not open, you use the keyboard that is still plugged into the box. The management address is gone, so SSH and the web page have nothing to reach, and the serial console still answers. You use that console, and a poll, a VPN, or a heat map aimed at the dead address cannot get you in.
Full Explanation
A serial console connects to the switch's console port and presents the management interface without using the production IP address. SSH and the web interface both target the management address, and that address is gone, so those paths fail even though the switch is still sitting in the rack and forwarding. The console still responds, which makes it the way in. SNMP polls a device at a network address, commonly the same management address. If the switch will not answer SSH or the web page at that address, an SNMP poll to it will not open a session either. A client VPN can reach a network only if the far address is up and the tunnel can land. Aiming the VPN at the address the switch has lost recreates the same failure. A wireless heat map records signal levels from a survey. It is not a management channel, and a drawing from last month cannot type a command on this switch. Exam caveat: the console still needs physical access and the correct credentials. Out-of-band reachability does not bypass the login. Operational check: connect to the console, restore the management address and its VLAN, and only then confirm SSH and the web interface respond at that address.