How to Configure Star SysLog Sender for Secure Remote LoggingSecure remote logging is essential for monitoring, troubleshooting, and auditing systems across networks. Star SysLog Sender is a lightweight, flexible tool that forwards syslog messages from devices and applications to centralized log collectors. This guide walks you through planning, installing, configuring, and hardening Star SysLog Sender to reliably and securely send logs to remote destinations.
What you’ll need
- A machine (Linux/Windows) with network access to your log collector (e.g., syslog-ng, rsyslog, Graylog, Splunk, or a SIEM).
- Administrative access to edit configuration files and manage services.
- TLS certificates or a VPN if you’ll use encrypted transport.
- Star SysLog Sender binary or package for your platform.
- Basic knowledge of syslog message formats (RFC 5424/RFC 3164) and network ports (UDP 514, TCP 514 or custom ports).
Planning the deployment
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Define logging goals
- Decide which hosts and applications require centralized logging.
- Identify log retention, indexing, and alerting requirements at the collector side.
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Choose transport and format
- For security, prefer TCP with TLS over UDP. UDP is faster but unreliable and unencrypted.
- Choose message format: RFC 5424 is structured and preferred for modern log collectors; RFC 3164 is legacy.
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Determine authentication & encryption
- Use TLS with certificate-based authentication when possible.
- If certificate management is impractical, place traffic inside a site-to-site VPN.
- Restrict sending hosts by IP allowlists at the collector and on network ACLs.
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Plan for reliability & performance
- Configure batching, retries, backpressure, and local buffering on intermittent networks.
- Monitor queue lengths and dropped messages.
- Consider rate limiting and log filtering to reduce noise.
Installing Star SysLog Sender
Note: replace package names and commands with platform-appropriate equivalents.
Linux (systemd example)
- Download the package or binary to /usr/local/bin and make executable:
sudo curl -o /usr/local/bin/star-syslog-sender https://example.com/star-syslog-sender sudo chmod +x /usr/local/bin/star-syslog-sender - Create a systemd service file /etc/systemd/system/star-syslog-sender.service: “` [Unit] Description=Star SysLog Sender After=network.target
[Service] ExecStart=/usr/local/bin/star-syslog-sender –config /etc/star-syslog-sender/config.yml Restart=on-failure User=syslog Group=syslog
[Install] WantedBy=multi-user.target
3. Reload systemd and start: sudo systemctl daemon-reload sudo systemctl enable –now star-syslog-sender
Windows - Use the provided installer or run the executable as a service using NSSM or Windows Service Wrapper. Configure the path to the config file in the service parameters. --- ### Configuration basics Star SysLog Sender typically uses a YAML or JSON config. Example YAML skeleton: ```yaml sender: name: "webserver-01" format: rfc5424 local_bind: 0.0.0.0:0 destinations: - name: "central-syslog" protocol: tcp host: 10.0.0.5 port: 6514 tls: enabled: true ca_file: /etc/star-syslog-sender/ca.pem cert_file: /etc/star-syslog-sender/client.pem key_file: /etc/star-syslog-sender/client.key verify_peer: true retries: 5 retry_interval_seconds: 10 batch_size: 100 buffer_dir: /var/lib/star-syslog-sender/queue max_buffer_size_mb: 512 rate_limit_per_sec: 200 filters: - type: exclude facility: "debug" program: "noisy-daemon" Key fields explained:
- format: “rfc5424” vs “rfc3164”.
- protocol: “udp” or “tcp” (prefer tcp).
- tls: provide CA, client cert and key if using mutual TLS. Set verify_peer to true to enforce server cert validation.
- buffer_dir/max_buffer_size_mb: local spool for reliability during outages.
- retries/retry_interval_seconds: delivery retry policy.
- batch_size: number of messages per network send.
- filters: drop or mask sensitive fields before sending.
Enabling TLS (recommended)
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Obtain certificates
- Use a trusted CA, internal PKI, or Let’s Encrypt (for resolvable hostnames).
- For mutual TLS, create and sign client certificates for each sending host.
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Configure the sender
- Point to CA, client cert, and key in the config (see example above).
- Set verify_peer: true and optionally require_server_name: “collector.example.com”.
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Configure the collector
- Enable TLS listening on its syslog endpoint (e.g., rsyslog + imtcp with GTLS).
- Configure collector to require client certificate verification if using mTLS.
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Test TLS connectivity
- Use openssl s_client:
openssl s_client -connect collector.example.com:6514 -CAfile ca.pem -cert client.pem -key client.key - Check for successful handshake and certificate validation.
- Use openssl s_client:
Filters and sensitive data handling
- Drop or mask PII before sending. Use filters to remove fields like credit card numbers, usernames, or tokens.
- Example: redact patterns matching SSN or auth token, or replace values with “[REDACTED]”.
- Keep structured local logs for forensic needs, but ensure they are encrypted at rest.
Reliability, buffering, and backpressure
- Local spool: enable buffer_dir so messages queue to disk if the collector is unavailable. Set sensible max_buffer_size_mb to avoid disk exhaustion.
- Acknowledge model: prefer TCP with app-level ACKs if supported, otherwise tune retries and timeouts.
- Backpressure handling: configure the sender to slow ingestion when the send queue grows. Use rate_limit_per_sec and smaller batch_size during peak loads.
- Monitoring: export metrics (queue length, send rate, errors) to Prometheus or local logs for alerting.
Monitoring & alerting
- Instrument the sender to expose metrics: sent/sec, failed/sec, queue_length, tls_errors.
- Create alerts for sustained queue growth, TLS handshake failures, or high error rates.
- Periodically verify log integrity: check that important events (logins, config changes) appear at the collector.
Firewall and network considerations
- Open only required outbound ports (e.g., TCP 6514) from sending hosts.
- Limit inbound access to the collector to known sender IPs.
- Use network ACLs or security groups to isolate logging traffic.
- If using UDP, accept that message loss can occur — use for non-critical, high-volume telemetry only.
Troubleshooting checklist
- Verify network connectivity: ping/traceroute and port checks (telnet or nc).
- Confirm TLS: openssl s_client for handshake; check certificate chain and validity.
- Inspect local sender logs for errors and stack traces.
- Ensure time sync (NTP) on both sender and collector for certificate validation and accurate timestamps.
- Check disk usage of buffer_dir; clear or expand if full.
- Validate message format compatibility (RFC 5424 vs 3164); enable or adjust parser on the collector.
Example: Minimal secure config (RFC 5424, TLS)
sender: name: "app-server-3" format: rfc5424 destinations: - name: "primary-collector" protocol: tcp host: collector.example.internal port: 6514 tls: enabled: true ca_file: /etc/ssl/certs/logging-ca.pem cert_file: /etc/ssl/certs/app-server-3.pem key_file: /etc/ssl/private/app-server-3.key verify_peer: true retries: 10 retry_interval_seconds: 15 buffer_dir: /var/lib/star-syslog-sender/queue max_buffer_size_mb: 1024 Security hardening checklist
- Use TLS with server verification; enable mutual TLS where possible.
- Enforce least privilege for the sender process (run as non-root).
- Protect private keys: restrict filesystem permissions (600) and limit access.
- Rotate certificates periodically and have an automated renewal process.
- Limit log data sent: filter out unnecessary or sensitive fields.
- Audit sender configuration and logs regularly.
Summary
Configuring Star SysLog Sender for secure remote logging involves choosing encrypted transport (TCP+TLS), proper certificate management, local buffering for reliability, filtering to remove sensitive data, and monitoring for operational health. With TLS, careful firewall rules, and attention to performance and storage, Star SysLog Sender can be a robust component of your centralized logging pipeline.
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