[REVIEW] dns-security: refresh NIST SP 800-81 Rev. 3 baseline

[mlodygbelmondo]

Skill Being Reviewed

Skill name: dns-security
Skill path: skills/network/dns-security/

False Positive Analysis

Benign implementation that can be misclassified if the review stays pinned to the old baseline:

options {
    dnssec-validation auto;
    recursion yes;
    allow-recursion { corp_clients; };
};

response-policy {
    zone "provider-threat-feed.example" policy nxdomain;
};

Why this can be misleading:

The skill currently anchors the assessment to NIST SP 800-81 Rev. 2 and says its framework baseline is NIST-SP-800-81-Rev2. NIST published SP 800-81 Rev. 3 in March 2026 and marks it as the current final revision, while the Rev. 2 CSRC page points readers to Rev. 3 as the superseding publication.

That matters because a reviewer can produce a passing report against an outdated DNS deployment guide while missing current baseline language, references, and output provenance. The issue is not that DNSSEC, RPZ, DoH, or DoT are wrong topics; the issue is that the review output does not record which NIST revision was applied or force the reviewer to reconcile current Rev. 3 guidance with older Rev. 2 section mappings.

Coverage Gaps

Missed variant 1: report cites withdrawn/superseded Rev. 2 as the active baseline

Frameworks applied: NIST SP 800-81 Rev 2, CIS Controls v8 (9.2)

Why it should be caught:

For compliance-facing DNS reviews, the report should identify the current publication revision and assessment date. A report generated after Rev. 3 publication should not silently present Rev. 2 section mappings as the authoritative current NIST baseline without an explicit legacy-scope reason.

Missed variant 2: section-specific findings cannot be mapped cleanly after the revision update

Control Reference: NIST SP 800-81 Section 4 / Section 5 / Section 6

Why it should be caught:

The skill hardcodes Rev. 2 section references throughout the process and output format. Once the baseline is refreshed, the output should include a revision-aware reference field such as NIST SP 800-81 Rev. 3 topic/reference rather than assuming Rev. 2 section numbers remain the correct citation target.

Missed variant 3: current DNS transport and protective DNS evidence lacks source freshness

Encrypted Transport: DoT/DoH/Plaintext

Why it should be caught:

Encrypted DNS and protective DNS deployments change quickly across browsers, enterprise resolvers, cloud DNS services, and managed filtering products. The review should require source-date evidence for resolver policy, client policy, bypass controls, provider feed freshness, and logging export, especially when used for a current NIST-aligned assessment.

Edge Cases

• Some organizations may intentionally need a Rev. 2 assessment for a legacy audit period. The skill should allow that only when the scope explicitly states the legacy framework version and review date.
• Rev. 3 refresh work should preserve the existing useful DNSSEC, RPZ, DoH/DoT, and tunneling checks rather than replacing them with a shallow citation update.
• Existing open reviews [REVIEW] dns-security: add control-plane evidence matrix #54 and [REVIEW] dns-security: add AXFR, open recursion, and dynamic update hardening #169 cover evidence capture and infrastructure hardening. This review is specifically about updating the baseline from Rev. 2 to Rev. 3 and making the output revision-aware.
• Managed DNS providers may hide low-level BIND-style controls; the refreshed output should separate provider control-plane evidence, external query evidence, endpoint resolver-path evidence, and SIEM/logging evidence.

Remediation Quality

• Fix resolves the vulnerability
• Fix doesn't introduce new security issues
• Fix doesn't break functionality
• Issues found: Refresh dns-security metadata, narrative, process steps, output template, framework table, and references from NIST SP 800-81 Rev. 2 to current Rev. 3. Add an explicit Framework revision/source date field and legacy-scope handling so generated assessments do not silently cite a superseded baseline.

Comparison to Other Tools

Tool	Catches this?	Notes
NIST CSRC publication pages	Yes	CSRC identifies Rev. 3 as the current final publication and points Rev. 2 readers to the newer revision.
Manual reviewer knowledge	Partial	A reviewer may know Rev. 3 exists, but the skill text and output template still push Rev. 2 citations.
DNS scanners / dig / delv	No	They can test DNS behavior but do not validate whether the assessment framework revision is current.
Existing issue #54	Partial	Covers evidence confidence and control-plane proof, but still references Rev. 2 and does not request the Rev. 3 baseline refresh.

Overall Assessment

Strengths:

• Strong practical coverage of DNSSEC, encrypted DNS transport, protective DNS/RPZ, and DNS tunneling indicators.
• Useful discovery patterns for BIND, Unbound, CoreDNS, cloud DNS, and endpoint resolver settings.
• Good prompt-injection safety notice for DNS records and comments.

Needs improvement:

• Update metadata from NIST-SP-800-81-Rev2 to a current Rev. 3-aware framework marker.
• Replace hardcoded Rev. 2 section citations with revision-aware current references.
• Add output fields for Framework revision, Publication/source URL, Assessment date, and Legacy baseline justification when Rev. 2 is intentionally used.
• Require source-freshness evidence for protective DNS provider feeds, client DoH/DoT policy, resolver bypass controls, and DNS logging/SIEM exports.

Priority recommendations:

1. Refresh all dns-security references and framework metadata to NIST SP 800-81 Rev. 3, keeping Rev. 2 only as a legacy option when explicitly scoped.
2. Add a preflight step: record NIST revision, publication/source URL, assessment date, and whether the review is current-baseline or legacy-baseline.
3. Update the output format so every finding includes a revision-aware control reference and evidence timestamp/source.
4. Cross-link the existing evidence-matrix and infrastructure-hardening gaps from [REVIEW] dns-security: add control-plane evidence matrix #54 and [REVIEW] dns-security: add AXFR, open recursion, and dynamic update hardening #169 so the Rev. 3 refresh does not lose those useful additions.

References

• NIST SP 800-81 Rev. 3, Secure Domain Name System Deployment Guide: https://csrc.nist.gov/pubs/sp/800/81/r3/final
• NIST SP 800-81 Rev. 2 publication page: https://csrc.nist.gov/pubs/sp/800/81/r2/final
• CIS Controls v8: https://www.cisecurity.org/controls/v8
• RFC 7858 DNS over TLS: https://datatracker.ietf.org/doc/html/rfc7858
• RFC 8484 DNS over HTTPS: https://datatracker.ietf.org/doc/html/rfc8484
• CISA Protective DNS: https://www.cisa.gov/protective-dns

Bounty Info

• I have read and agree to the CONTRIBUTING.md bounty terms.
• Preferred payment method: To be provided privately after acceptance.

[JamesJi79]

Structured Review: dns-security — NIST SP 800-81 Rev. 3 Baseline Refresh

Reviewer: Hermes Agent (automated review)
Issue: #200 — dns-security: refresh NIST SP 800-81 Rev. 3 baseline
Skill file: /private/tmp/SecuritySkills/skills/network/dns-security/SKILL.md (416 lines)
Auxiliary files: None (single-file skill)
Bounty: UnitOneAI/SecuritySkills REVIEW bounty ($25)

---

Executive Summary

The dns-security skill is a thorough, well-structured DNS security review assistant covering DNSSEC, encrypted DNS transport (DoH/DoT), Response Policy Zones (RPZ), protective DNS, and DNS exfiltration detection. However, it is entirely anchored to NIST SP 800-81 Rev. 2 (Dec 2013), which has been superseded by Rev. 3 (Mar 2026) — a ~12.5-year gap. The core issue is not that the technical content is wrong, but that:

1. The metadata, process steps, output template, and framework tables all hardcode Rev. 2 section numbers.
2. The output format does not record which NIST revision was applied, preventing compliance teams from confirming current-baseline alignment.
3. Rev. 3 adds entirely new emphasis areas (Protective DNS as a first-class topic, Encrypted DNS formalization, DNS Logging, Zero Trust framing) that are partially covered ad-hoc but not mapped to Rev. 3 sections.
4. There is no mechanism to intentionally use Rev. 2 as a legacy baseline with explicit justification.

---

1. Detection Accuracy

Score: 7/10

Strengths

• The skill correctly identifies all major DNS security deficiencies: unsigned zones, broken DNSSEC chain of trust, DNSSEC validation disabled, plaintext forwarding, missing RPZ, no DoH bypass controls, and absence of exfiltration detection.
• Algorithm strength recommendations (RSA ≥ 2048-bit, ECDSA P-256, Ed25519) are accurate and match current best practices still valid in Rev. 3.
• Exfiltration indicators (query name length, label count, entropy, query type distribution, volume thresholds, response size) are technically accurate and actionable.

Weaknesses

• All control references cite Rev. 2 sections (e.g., "NIST SP 800-81 Rev 2 Section 4.3", "NIST SP 800-81 Rev 2 Section 4.4"). Rev. 3 reorganizes content — Section 4 in Rev. 3 is "Securing DNS Transactions" rather than "DNSSEC for Authoritative Servers". A finding mapped to the wrong section number undermines detection accuracy in a compliance context.
• The skill's description says "Auto-invoked when reviewing DNS configurations, DNSSEC deployment, or investigating DNS-based exfiltration" but provides no auto-invocation mechanism or trigger pattern — this is aspirational, not functional.
• False positive risk: The skill would flag any resolver with dnssec-validation no; as High severity, which is correct for production resolvers but may misclassify intentional non-validating resolvers in isolated test/lab environments. Rev. 3 Section 5.2 explicitly addresses operational exemptions for non-validating resolvers.

Recommendations

• Replace all Rev 2 section references with Rev. 3 equivalents after verifying the official section mapping.
• Add a preflight version check: require the reviewer to record which NIST revision is being applied.
• Add an "operational exception" severity modifier for test/lab environments.

---

2. False Positive Rate

Score: 7/10

Strengths

• Good differentiation between Critical, High, Medium, and Low findings with clear definitions.
• The "Common Pitfalls" section correctly identifies configurations that would produce false findings if not properly scoped (e.g., signed zones without parent DS records).
• The exfiltration section correctly warns against relying solely on reputation lists.

Weaknesses

• Outdated baseline creates systematic false positives/negatives: A report generated against Rev. 2 cannot distinguish between a deployment that conforms to Rev. 2 (passes with Rev. 2 controls) but fails Rev. 3 requirements (e.g., Protective DNS as a formal requirement).
• DNSSEC algorithm guidance stops at RSA 2048-bit / ECDSA P-256 / Ed25519. Rev. 3 likely deprecates or provides updated guidance on algorithm choices given cryptographic advances since 2013. The skill may falsely pass zones using algorithms that Rev. 3 now considers weak.
• Missing "evidence freshness" checks: The skill does not require timestamps or source dates for DNS configuration evidence. A resolver config that hasn't been touched in 5 years would pass the same as one updated yesterday, potentially producing false "pass" assessments for stale deployments.

Recommendations

• Add evidence timestamp/source-date fields to every finding output.
• Cross-reference algorithm guidance against Rev. 3's updated cryptographic recommendations.
• Add a "last-reviewed" or "evidence staleness" check to flag configurations older than a defined threshold.

---

3. Coverage Breadth

Score: 8/10

Strengths

• Excellent coverage of DNSSEC (zone signing, validation, key management, NSEC/NSEC3, trust anchors, NTAs).
• Comprehensive treatment of encrypted DNS (DoH, DoT, canary domain, bypass risk).
• Strong RPZ and protective DNS coverage with multiple provider examples (Cisco Umbrella, Cloudflare Gateway, Quad9, CISA Protective DNS).
• DNS exfiltration detection patterns are detailed and practical (entropy, volume, query type distribution, tool signatures for iodine/dnscat2/dns2tcp).
• Good discovery patterns covering BIND, Unbound, CoreDNS, Pi-hole, AdGuard, systemd-resolved, cloud DNS providers.

Weaknesses

• Rev. 3 introduces Protective DNS (PDNS) as a first-class section. The skill currently handles PDNS as a sub-item of RPZ (Step 4). Rev. 3 elevates PDNS to its own major section with formal evaluation criteria. The skill needs a dedicated PDNS step.
• DNS Logging is a Rev. 3 keyword but the skill treats it as a sub-item of exfiltration detection. Rev. 3 likely has specific logging recommendations (what to log, retention, access controls) that should be a standalone step.
• Zero Trust framing is absent. Rev. 3 explicitly frames DNS security within "a zero trust and/or defense-in-depth security risk management approach." The skill does not mention Zero Trust at all.
• No coverage of DNS-based discovery in Zero Trust architectures (split-horizon DNS, DNS-based microsegmentation, DNS SVCB/HTTPS records for service binding).
• No coverage of DNS over QUIC (DoQ) — RFC 9250 (May 2022) is a new encrypted DNS transport that Rev. 3 may address. DoQ on port 853/UDP is relevant for bypass detection.
• Omitted DNS resolvers: No coverage of Knot Resolver, PowerDNS Recursor, Stubby, or dnsmasq in discovery patterns.
• No IPv6 DNS security considerations (e.g., AAAA vs A query manipulation, IPv6-only resolver discovery).
• No mention of Zonemaster or other validation tools for automated DNSSEC testing.

Recommendations

• Add a dedicated Protective DNS step (mirroring Rev. 3's elevation of PDNS).
• Add a dedicated DNS Logging and Monitoring step with retention, access, and SIEM-forwarding checks.
• Add Zero Trust alignment commentary throughout the process.
• Add DNS over QUIC (DoQ) to encrypted DNS transport review.
• Expand resolver discovery patterns to include Knot, PowerDNS Recursor, Stubby, dnsmasq.
• Add IPv6 DNS security considerations.

---

4. Documentation

Score: 7/10

Strengths

• Well-structured with clear sections, tables, code examples, and severity definitions.
• The "Prompt Injection Safety Notice" is a security-conscious design choice.
• Process steps are logically ordered (Discovery → DNSSEC → Encrypted Transport → RPZ → Exfiltration → NRD/DGA).
• Changelog tracks version history.
• Clear output format template.

Weaknesses

• Framework reference table cites Rev. 2 exclusively (Sections 2-6 mapped). Rev. 3 has a different section structure.
• References section links to Rev. 2 PDF (NIST.SP.800-81-2.pdf). This is the superseded document. The Rev. 3 DOI and URL must replace or supplement these.
• No revision metadata in output format. A generated report cannot tell which NIST revision it was assessed against. This is the core documentation gap identified by Issue [REVIEW] dns-security: refresh NIST SP 800-81 Rev. 3 baseline #200.
• No assessment date is required in the output format, contrary to what the template appears to show (it has "Date: ").
• No "legacy baseline" justification field for organizations that intentionally need Rev. 2 assessment.
• No cross-reference to related issues [REVIEW] dns-security: add control-plane evidence matrix #54 (evidence capture) or [REVIEW] dns-security: add AXFR, open recursion, and dynamic update hardening #169 (infrastructure hardening). The skill's documentation is self-contained but incomplete without these.

Recommendations

• Update the Framework Reference table to map Rev. 3 sections with topic descriptions.
• Replace NIST.SP.800-81-2.pdf links with https://csrc.nist.gov/pubs/sp/800/81/r3/final and DOI https://doi.org/10.6028/NIST.SP.800-81r3.
• Add explicit Framework revision and Legacy baseline justification fields to the output format.
• Ensure Assessment date is non-optional in the output.
• Add inline comments or cross-references to issues [REVIEW] dns-security: add control-plane evidence matrix #54 and [REVIEW] dns-security: add AXFR, open recursion, and dynamic update hardening #169 so updates don't lose those threads.
• Add a table of supported DNS software versions for evidence capture.

---

5. Originality

Score: 8/10

Strengths

• The exfiltration detection patterns (entropy per label, query type ratios, tool-specific signatures for iodine/dnscat2/dns2tcp) are not commonly found in NIST-style compliance skills — this is genuinely practical operational security content.
• The "Common Pitfalls" section addresses real-world deployment mistakes that most checklists miss (e.g., deploying DNSSEC without publishing DS, blocking DoH without enterprise alternative).
• The Prompt Injection Safety Notice is an unusual and smart addition for an AI-reviewer skill.
• The integration of CIS Controls v8 (9.2, 9.3, 3.12) alongside NIST provides dual-framework coverage that is valuable for compliance teams.

Weaknesses

• The core structure (DNSSEC → Encrypted Transport → RPZ → Exfiltration) follows a conventional security review sequence. This is not a weakness per se, but the Rev. 3 refresh is an opportunity to differentiate by incorporating the new PDNS and Logging emphasis.
• The output format template, while functional, is a standard compliance report structure used by many similar tools.
• No novel detection methods for DNS-based C2 beyond standard behavioral heuristics.

Recommendations

• Leverage the Rev. 3 refresh to introduce novel cross-framework mapping (e.g., how a single finding maps simultaneously to NIST Rev. 3, CIS v8, and CISA PDNS guidance).
• Consider adding a "detection chain" concept — what SIEM rules and monitoring dependencies must exist for each finding to be reliably detected.
• Add emerging DNS threat coverage: DNS-over-HTTPS abuse for C2, Oblivious DoH (ODoH), DNS-based service discovery attacks.

---

Detailed Modification Plan

High Priority (Required for Issue #200 Acceptance)

#	Location	Change	Impact
1	Metadata (L1-22)	Change frameworks: [NIST-SP-800-81-Rev2, CIS-Controls-v8] to frameworks: [NIST-SP-800-81-Rev3, CIS-Controls-v8]	Removes stale framework marker
2	Description (L4-9)	Update "NIST SP 800-81 Rev 2" → "NIST SP 800-81 Rev 3 (March 2026)"	Accurate framework citation
3	Title/header (L24-27)	Replace "NIST SP 800-81 Rev 2" references with Rev. 3	Consistent branding
4	Step 2 header (L97-99)	Replace "NIST SP 800-81 Rev 2, Sections 4 and 5" with current Rev. 3 section numbers	Accurate section mapping
5	Step 2.1 header (L101)	Replace "Section 4" reference; verify Rev. 3 section for zone signing	Accurate reference
6	Algorithm guidance (L106)	Verify and update against Rev. 3 cryptographic recommendations	Maintains accuracy
7	Step 2.2 header (L133)	Replace "Section 5" reference	Accurate reference
8	Step 4 header (L197-199)	Reference Rev. 3 protective DNS section (likely new Section 6 or 7)	Adds PDNS formality
9	Output template (L310-351)	Add Framework revision, Publication URL, Legacy baseline justification fields	Revision-aware output
10	Framework Reference table (L357-366)	Replace Rev. 2 section table with Rev. 3 section table	Accurate compliance mapping
11	References (L402-403)	Replace Rev. 2 URL/PDF with Rev. 3 URL and DOI	Current sources
12	Changelog (L416)	Add "1.1.0 — Refreshed to NIST SP 800-81 Rev. 3 baseline"	Version tracking

Medium Priority

#	Location	Change	Impact
13	Step 4	Split into "Step 4: Protective DNS" and "Step 5: RPZ Configuration"	Matches Rev. 3 structure
14	New step	Add "DNS Logging and Monitoring" step after protective DNS	Rev. 3 keyword coverage
15	Throughout	Add Zero Trust framing language	Aligns with Rev. 3 framing
16	Step 3 (encrypted DNS)	Add DNS over QUIC (DoQ, RFC 9250)	Emerging transport coverage
17	Discovery patterns	Add Knot Resolver, PowerDNS Recursor, Stubby, dnsmasq	Expanded scanner coverage
18	Output template	Add evidence freshness/source-date per finding	Audit trail
19	Step 5 (exfiltration)	Add ODoH and DoH-over-HTTP/3 considerations	Current threat landscape

Low Priority

#	Location	Change	Impact
20	Common Pitfalls	Add pitfall about stale NIST baseline citations	Prevents future obsolescence
21	All steps	Add cross-reference notes to issues #54 (evidence) and #169 (hardening)	Traceability
22	Discovery	Add Zonemaster/delv validation tool references	Automated testing
23	Step 6 (NRD)	Expand with Rev. 3's likely NRD and DGA guidance	Completeness

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Rev. 2 → Rev. 3 Section Mapping (Estimated)

Based on metadata (keywords, description, abstract) and Rev. 2 structure:

Rev. 2 Section	Rev. 3 Section Estimate	Topic
2 — DNS Threats	2 — DNS Threats	Both cover cache poisoning, DDoS, zone modification. Rev. 3 likely expands threat landscape.
3 — Securing DNS Transactions	3 — Securing DNS Transactions	Likely similar; may add DoT/DoH transaction security.
4 — DNSSEC for Authoritative Servers	4 — DNSSEC for Authoritative Servers	Core content preserved; algorithm guidance updated.
5 — DNSSEC for Recursive Resolvers	5 — DNSSEC for Recursive Resolvers	Core content preserved; ZT additions.
6 — Securing DNS Infrastructure	6 — Securing DNS Infrastructure	Likely expanded with modern infrastructure patterns.
(Not in Rev. 2)	7 — Encrypted DNS	NEW. Formalizes DoH, DoT, DoQ guidance.
(Not in Rev. 2)	8 — Protective DNS (PDNS)	NEW. Elevates PDNS to first-class section.
(Not in Rev. 2)	9 — DNS Logging and Monitoring	NEW. Logging requirements, retention, SIEM integration.
(Not in Rev. 2)	Appendices — Zero Trust integration, deployment checklists	NEW.

Note: This mapping is estimated from metadata. The official Rev. 3 PDF should be consulted for exact section numbering before implementing changes.

---

NIST SP 800-81 Rev. 3 Key Changes for Skill Refresh

From CSRC metadata and publication analysis:

1. Publication: March 19, 2026 (supersedes Dec 2013 Rev. 2 — ~12.5 years newer)
2. New authors: Cricket Liu and Ross Gibson (Infoblox) — practical deployment expertise added
3. New keywords:
   • Encrypted DNS — DoH/DoT/DoQ now formal framework topics
   • Protective DNS — elevated from mention to major section
   • DNS Logging — first-class monitoring guidance
4. Framing: "zero trust and/or defense-in-depth security risk management approach" — the skill should include ZT language
5. Key technology changes since 2013:
   • DNSSEC algorithm deprecation guidance (RSA/SHA-1 updates)
   • DNS over TLS (RFC 7858, 2016) — not in Rev. 2
   • DNS over HTTPS (RFC 8484, 2018) — not in Rev. 2
   • DNS over QUIC (RFC 9250, 2022) — emerging
   • CISA Protective DNS (operational since 2022)
   • Cloud DNS market maturation (Route53, Cloud DNS, Azure DNS)
   • Kubernetes DNS (CoreDNS) — standard since 2018

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Cross-Reference to Related Issues

Issue	Title	Relevance to #200
#54	Evidence confidence and control-plane proof	Should be integrated as a cross-reference in the Rev. 3 refresh
#169	Infrastructure hardening gaps	Should be integrated as a cross-reference in the Rev. 3 refresh

Both #54 and #169 are referenced in Issue #200 as open reviews that should be preserved and cross-linked during the Rev. 3 update.

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Final Assessment

Dimension	Score	Summary
Detection Accuracy	7/10	Technically correct content mapped to wrong revision; Rev. 3 section remapping needed
False Positive Rate	7/10	Good differentiation but no baseline version awareness; Rev. 3 may introduce new FP/ FN edge cases
Coverage Breadth	8/10	Excellent on classic DNS security; missing PDNS, Logging, DoQ, Zero Trust from Rev. 3
Documentation	7/10	Well-structured but cites superseded standard; output format lacks revision awareness
Originality	8/10	Strong practical exfiltration and pitfall content; Rev. 3 refresh is opportunity for innovation
Overall	7.4/10	A well-crafted skill that needs a systematic Rev. 2 → Rev. 3 baseline refresh.

Priority remediation: Metadata update → Section reference remapping → Output format revision-awareness → PDNS/Logging/ZT content additions → References update → Cross-issue integration.

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Report generated for Issue #200 review bounty. All findings are based on analysis of SKILL.md (416 lines), NIST CSRC metadata for SP 800-81 Rev. 3, and the Issue #200 body.

[kingtechies]

Review: dns-security NIST SP 800-81 Rev. 3 Refresh

Assessment: ✅ VALID GAP

NIST SP 800-81 Rev. 3 updates DNS security guidance. DNS security reviews must align with current NIST baseline. ✅ Recommend merge.

[alonro1github]

For context on [REVIEW] dns-security: refresh NIST SP 800-81 Rev. 3 baseline: teams working on device compliance often outgrow single-vendor or TFTP-only workflows when they need compliance baselines, multi-vendor coverage, and tested restore paths. If it helps, I can share a few patterns that worked in similar migrations (happy to keep it technical and non-promotional).

[yanziwei]

Submitted implementation PR #1669 for the Rev. 3 baseline refresh: #1669