Start with the security outcome
Map your requirement to a specific failure mode. Blocking a known malicious domain calls for destination policy and relevant indicators. Authenticating signed DNS answers calls for DNSSEC validation. Query flooding requires access and workload controls. Suspected tunneling requires behavioral evidence and investigation.
These requirements can coexist, but they are not interchangeable. Encryption protects a DNS transport; it does not decide whether a domain is malicious. A resolver-side rate limit can bound work but cannot restore connectivity after an upstream link is saturated.
- Malicious destinations: evaluate request and response filtering and the sources behind the indicators.
- Answer integrity: verify DNSSEC behavior for signed, unsigned, and invalid data.
- Resolver abuse: review exposure, client access, rate limits, and response controls.
- Suspicious DNS activity: assess detector tuning, false positives, and the evidence available to investigate.
Compare deployment models and responsibilities
A managed DNS filtering service, a virtual resolver appliance, and DNS controls in a broader security product place operational responsibilities in different locations. For each candidate, establish where queries go, who operates the resolver, what happens during a connectivity failure, and how policy changes reach enforcement.
For a virtual appliance, review network placement, hypervisor support, resource allocation, updates, and recovery. For an externally operated service, verify connectivity dependencies, data handling, and the controls available to your administrators. Neither model is universally better; the appropriate choice depends on your service and operational requirements.
Raven is a virtual DNS appliance with recursive resolution and DNS security controls. Do not assume that this provides a hosted global resolver network, an endpoint roaming agent, built-in clustering, or internal Anycast. Confirm coverage for each client group through the actual deployment design.
Questions to ask before choosing a solution
Ask for observable behavior rather than a feature checklist alone. A policy demonstration should identify the input, the rule or signal, the returned DNS response, and the event that an operator can inspect. Use the same controlled cases for each candidate.
- Coverage: which clients use the controlled resolver, and what prevents unapproved DNS paths?
- Intelligence: where do indicators come from, how are updates applied, and how are false positives handled?
- Policy: are request and answer checks independent, and can operators distinguish blocking from observation?
- Privacy and evidence: what is collected, where is it stored, and what survives a restart?
- Integration: can the receiving event system prove delivery and preserve enough context for investigation?
- Failure: what happens when an upstream, feed, management service, or network path is unavailable?
- Operations: what capacity, licence, update, and recovery requirements apply to the proposed deployment?
Where Raven fits
Raven combines DNS Guard policies, domain and IP/CIDR indicators, threat feeds, and RPZ sources with recursive resolution. Optional local DNSSEC validation and separately enabled anomaly detectors cover additional trust and investigation needs. Operators can review Guard events and forward events to external systems through configured Syslog or webhook destinations.
The enforcement result depends on configuration and available evidence. Unknown malicious domains may not match an indicator. An anomaly is a signal to evaluate, and a log-only policy does not block traffic. Live Query is bounded and RAM-only, so long-term evidence requirements need a separate collection plan.
Use the platform guide to understand the combined workflow and the appliance guide to review deployment boundaries. Confirm product fit with your workload rather than assuming a throughput number, certification, supported hypervisor, or service-level commitment that has not been agreed.
Run a controlled proof of concept
Define test clients and approved test domains before changing production DNS. Record normal lookup behavior and application dependencies, then introduce policy on a limited group. Include legitimate traffic that resembles an anomaly so you can assess false positives as well as expected blocks.
Test the complete operational loop: apply a policy, observe the client response, find the event, verify external delivery if used, and exercise recovery. Use an agreed rollback procedure and compare results against written acceptance criteria before broad deployment.
Does DNS security replace other defenses?
No. DNS security adds controls at name resolution. It does not inspect every application payload, remove malware from endpoints, or cover connections that bypass the controlled DNS path. Combine it with appropriate network, endpoint, and incident-response controls.
Likewise, DNSSEC and encrypted DNS are not complete DNS security solutions on their own. They solve different trust and transport problems and should be evaluated alongside destination policy, service availability, and investigation needs.