CompTIA Network+ (N10-009)Network TroubleshootingMedium
A network administrator is performing a routine check of network devices. When attempting to log into a managed switch via SSH, the connection attempt consistently times out. Pinging the switch's management IP address is successful. Other services on the switch, such as SNMP, are also responding. Which of the following is the MOST likely cause of the SSH timeout?
- AThe switch's management VLAN is down.
- BThe SSH service is disabled or not configured on the switch.
- CThe administrator's workstation has an incorrect subnet mask.
- DThe switch has a duplicate IP address.
Show answer & explanationAnswer & explanation
Correct answer: B. The SSH service is disabled or not configured on the switch.
The ability to ping the switch and have other services like SNMP respond indicates that the switch is online, reachable at its IP address, and its network interface is functional. A consistent SSH timeout, while other services work, strongly suggests that the SSH service itself is either not running, disabled, or improperly configured on the switch.
Why the other options are wrong
- A. If the management VLAN were down, pinging the switch's IP would also fail.
- C. An incorrect subnet mask on the administrator's workstation would likely prevent it from reaching the switch at all, including pinging it.
- D. A duplicate IP address would cause intermittent connectivity for all services, not just reliably block SSH while allowing ping and SNMP.
Network Service Unavailability
A situation where a specific network application or protocol service on a device is unreachable or non-functional, even if the device itself is online.
- Device is pingable, but specific service (e.g., SSH, HTTP, FTP) fails.
- Often due to service being disabled, misconfigured, or firewalled on the device.
- Troubleshoot by checking service status, port listening, and device firewall rules.
Memory trick: The 'house' is there, but one 'door' won't open.