A web server platform failed over to a secondary datacenter due to a power failure, but alerting messages cease. Which port issue could cause this problem?

A web server platform failed over to a secondary datacenter due to a power failure, but alerting messages cease. Which port issue could cause this problem?

• A. Port 21 inbound at the primary datacenter
• B. Port 22 to the log server is blocked outbound
• C. Port 162 in DMZ is blocked inbound
• D. Port 162 in DMZ is blocked outbound

Answer: (B)

The thing being tested is whether alert delivery can reach the central log/alerting system. If alerting stops after a failover, the most likely issue is that the path used to send those alerts is being blocked. In many setups, centralized logging and alerting rely on outbound connections from the web server to the log server over SSH on port 22. If outbound traffic to the log server on port 22 is blocked, the server can’t forward logs or trigger remote alerts, so alerting ceases even though the application remains up in the secondary datacenter. The other options don’t fit as neatly: port 21 inbound at the primary datacenter affects FTP access into that DC and wouldn’t directly explain alerts stopping after failover; the SNMP trap port (162) in the DMZ would block SNMP-based alerts, but that would imply SNMP traffic is the alerting path and isn’t as universally implicated as SSH-based log forwarding in many deployments. In this scenario, the blocked outbound SSH path to the log server best explains why alerting stops after failover.

The thing being tested is whether alert delivery can reach the central log/alerting system. If alerting stops after a failover, the most likely issue is that the path used to send those alerts is being blocked. In many setups, centralized logging and alerting rely on outbound connections from the web server to the log server over SSH on port 22. If outbound traffic to the log server on port 22 is blocked, the server can’t forward logs or trigger remote alerts, so alerting ceases even though the application remains up in the secondary datacenter.

The other options don’t fit as neatly: port 21 inbound at the primary datacenter affects FTP access into that DC and wouldn’t directly explain alerts stopping after failover; the SNMP trap port (162) in the DMZ would block SNMP-based alerts, but that would imply SNMP traffic is the alerting path and isn’t as universally implicated as SSH-based log forwarding in many deployments. In this scenario, the blocked outbound SSH path to the log server best explains why alerting stops after failover.