Which support service is required to synchrony the time stamps in system logs from these devices?

SNMP (Simple Network Management Protocol) is used for monitoring and managing network device status and performance metrics, not for collecting or centralizing system log messages.

Syslog is the dedicated service for forwarding system event messages - including their timestamps - from routers, switches, servers, and other devices to a centralized Syslog server. Aggregating logs via Syslog allows administrators to review and correlate timestamped events across the entire infrastructure from one location, which is the function described in the question.

SMTP (Simple Mail Transfer Protocol) is the protocol for transferring email between mail servers and has no role in collecting or managing system log data.

DNS (Domain Name System) resolves hostnames to IP addresses and is entirely unrelated to log collection or timestamp management.