↳ GitHub sourceAnalytics ruleLow
Tailscale Premium: DERP relay traffic surge
Description
Identifies when a source node has more than 75 percent of its recent flows falling back to a DERP relay (Tailscale IsRelayed flag, traffic via 127.3.3.40). Operational signal useful for spotting policy drift.
- Rule type
- Scheduled
- Version
- 1.0.0
- Declared status
- Available
- Query frequency
- 15m
- Query period
- 15m
- Trigger
- gt 0
Declared MITRE coverage
Declared sources
Metadata from the source file. No dependencies inferred from KQL.
Connectors
Data types
KQL query
Original query, unchanged.
let minFlows = 20;
let relayedPctThreshold = 75.0;
Tailscale_Network_CL
| where TimeGenerated > ago(15m)
| summarize
TotalFlows = count(),
RelayedFlows = countif(IsRelayed)
by SrcNodeName, SrcUser, SrcOs, SrcTags=tostring(SrcTags)
| where TotalFlows >= minFlows
| extend RelayedPct = round(100.0 * RelayedFlows / TotalFlows, 1)
| where RelayedPct > relayedPctThreshold
| project SrcNodeName, SrcUser, SrcOs, SrcTags, TotalFlows, RelayedFlows, RelayedPct
| order by RelayedPct desc
Declared entities
Related content
Links established from declared identifiers and solution manifests.
Source provenance
GitHubDisplayed values come from files in Azure/Azure-Sentinel. They describe the published template, not your workspace configuration.
- Commit
9800e51↗- Source identifier
0a1c8d12-e7d3-4890-8b89-8d6dbc1be2f0
GSTEP / CATALOG TRACKING
Added to catalog : 16 Sept 2026 · 05:49 UTC
Last change observed : 16 Sept 2026 · 05:49 UTC