Log Center is the centralized log management app for Synology. According to the knowledge base, it can help you diagnose issues by doing the following:
- Search and filter local logs and logs received from other network devices
- Monitor log volume according to time or device
- Send notifications to administrators when specified events occur
- Send and receive logs from other network devices via syslog logging standard
- Specify log archival destination and create rules to automatically trigger log archival
For diagnosis tools, the RT2600ac documentation also mentions:
- Ping: used to test whether a destination IP address exists and can accept requests, and to help diagnose slow or failing connectivity
- Traceroute: used to examine the Internet pathway to a specific destination and understand how traffic is being routed
If you want to diagnose a failure, the knowledge base points to using Log Center for log search/filtering and Ping/Traceroute for network-path checks.
If you need the exact clicks for a specific symptom, the knowledge base excerpt here does not provide a step-by-step failure workflow.
Sources used: [1], [4], [8], [15]