diff --git a/.github/workflows/aur-publish.yml b/.github/workflows/aur-publish.yml
index 50eadd1b..d82f8192 100644
--- a/.github/workflows/aur-publish.yml
+++ b/.github/workflows/aur-publish.yml
@@ -39,10 +39,16 @@ jobs:
       - name: Install build and lint tooling
         run: |
           set -euo pipefail
-          pacman -Sy --noconfirm --needed base-devel namcap git curl
+          pacman -Sy --noconfirm --needed base-devel namcap git curl jq
 
       - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803 # v6
 
+      - name: Test the publish gate
+        # Fixture tests for the script the publish job below waits with. They
+        # run here, on every trigger, so a change to the gate is exercised
+        # before a release tag depends on it.
+        run: bash packaging/aur/test-await-package-runs.sh
+
       - name: Resolve package version
         id: ver
         env:
@@ -136,11 +142,21 @@ jobs:
   # or a manual dispatch (packaging-only republish with explicit tag + pkgrel).
   # Branch pushes and pull requests build+lint above but never reach this job.
   # Gated on aur-build so a package that fails to build/lint is never published.
+  # It also waits for every package-*.yml run on the tag to succeed before it
+  # pushes: the AUR must not point at a tag whose release assets are still
+  # uploading or failed, and once it does, withdrawing the tag breaks the AUR
+  # package (its b2sum pins the tag's source archive).
   # ───────────────────────────────────────────────────────────────────────────
   aur-publish-fips:
     name: Publish fips to AUR
     needs: aur-build
     runs-on: ubuntu-latest
+    # Above the gate's own 60-minute budget, so the gate reports a timeout
+    # rather than the runner killing it.
+    timeout-minutes: 90
+    permissions:
+      contents: read
+      actions: read
     if: >-
       github.event_name == 'workflow_dispatch'
       || (github.event_name == 'push'
@@ -180,6 +196,26 @@ jobs:
         with:
           ref: ${{ steps.tag.outputs.tag }}
 
+      # The gate script comes from this workflow's own revision, not the tag:
+      # a dispatch republishing a tag cut before the gate existed would not
+      # find it in the tag's tree. The workflows it waits on still come from
+      # the tag's tree, which is what the tag push triggered.
+      - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803 # v6
+        with:
+          path: gate-src
+          sparse-checkout: packaging/aur
+
+      - name: Wait for the tag's package workflows
+        env:
+          GH_TOKEN: ${{ github.token }}
+          TAG: ${{ steps.tag.outputs.tag }}
+        run: |
+          set -euo pipefail
+          SHA=$(git rev-parse 'HEAD^{commit}')
+          echo "Tag $TAG is at $SHA"
+          SHA="$SHA" WORKFLOW_DIR=.github/workflows \
+            bash gate-src/packaging/aur/await-package-runs.sh
+
       - name: Patch PKGBUILD with pkgver, pkgrel, conflicts, and b2sums
         env:
           TAG: ${{ steps.tag.outputs.tag }}
diff --git a/packaging/aur/PKGBUILD b/packaging/aur/PKGBUILD
index ac758a6d..9cdbc749 100644
--- a/packaging/aur/PKGBUILD
+++ b/packaging/aur/PKGBUILD
@@ -6,7 +6,7 @@ pkgdesc="Distributed, decentralized network routing protocol for mesh nodes"
 url="https://github.com/jmcorgan/fips"
 license=('MIT')
 arch=('x86_64')
-depends=('gcc-libs' 'glibc')
+depends=('dbus' 'gcc-libs' 'glibc')
 makedepends=('cargo' 'clang')
 optdepends=('systemd-resolved: .fips DNS resolution')
 conflicts=('fips-git' 'fips-git-debug')
diff --git a/packaging/aur/README.md b/packaging/aur/README.md
index ed5a2991..8017349f 100644
--- a/packaging/aur/README.md
+++ b/packaging/aur/README.md
@@ -20,6 +20,8 @@ This directory contains Arch Linux packaging files for two AUR packages:
 | `fips-dns.service` | Symlink to `../debian/fips-dns.service` |
 | `build-aur.sh` | Local `fips-git` build plus namcap validation (run by `make aur`) |
 | `patch-pkgbuild.sh` | Rewrites `pkgver`, `pkgrel`, `conflicts`, `options`, and `b2sums` in the PKGBUILD at publish time |
+| `await-package-runs.sh` | Holds the AUR publish until every `package-*.yml` run for the release tag has succeeded |
+| `test-await-package-runs.sh` | Fixture tests for `await-package-runs.sh`, run by the `aur-build` job |
 
 Both PKGBUILDs reference files from `packaging/debian/` (service files) and
 `packaging/common/` (config files) at build time. These are pulled from the
diff --git a/packaging/aur/await-package-runs.sh b/packaging/aur/await-package-runs.sh
new file mode 100755
index 00000000..dc2fcecd
--- /dev/null
+++ b/packaging/aur/await-package-runs.sh
@@ -0,0 +1,131 @@
+#!/usr/bin/env bash
+# Wait until every package workflow run for a release tag has succeeded.
+#
+# The AUR publish job runs this before it pushes a new pkgver, so the AUR never
+# points at a tag whose release assets are still uploading or failed to build.
+# Each package-*.yml workflow uploads its assets from a `release` job inside
+# the same run, so a successful tag run means that workflow's assets are up.
+#
+# The population is discovered from the checked-out tree rather than listed
+# here: the package-*.yml files at the tag are the workflows the tag push
+# triggered. Finding none is a failure, never a pass.
+#
+# A tag push and the branch push of the same commit each start a run with the
+# same head_sha; only the tag run carries the tag name in head_branch, so runs
+# are matched on both. If the tag was re-pushed at the same commit, the newest
+# matching run decides.
+#
+# Required environment variables:
+#   GITHUB_REPOSITORY - owner/repo
+#   TAG               - release tag (e.g. v0.5.1)
+#   SHA               - the commit the tag points at
+#   GH_TOKEN          - token with actions:read (read by gh; not checked here)
+# Optional:
+#   WORKFLOW_DIR   - where to discover package-*.yml (default .github/workflows)
+#   AWAIT_POLLS    - number of polls before giving up (default 60)
+#   AWAIT_INTERVAL - seconds between polls (default 60)
+#   DISCOVER_ONLY  - if set to 1, print the discovered workflows and exit
+#
+# Exit status: 0 when every discovered workflow has a successful tag run;
+# 1 at once when a tag run concludes anything but success; 1 when the poll
+# budget runs out with any workflow unobserved, not finished, or unreadable.
+
+set -euo pipefail
+
+: "${GITHUB_REPOSITORY:?GITHUB_REPOSITORY must be set}"
+: "${TAG:?TAG must be set}"
+: "${SHA:?SHA must be set}"
+WORKFLOW_DIR="${WORKFLOW_DIR:-.github/workflows}"
+AWAIT_POLLS="${AWAIT_POLLS:-60}"
+AWAIT_INTERVAL="${AWAIT_INTERVAL:-60}"
+
+# How to recover once the cause of a failure is fixed. A workflow_dispatch run
+# of a package workflow is not a push run of the tag and never satisfies this
+# gate; re-running the failed jobs of the tag's own run keeps it one.
+RECOVERY="If a run failed: use \"Re-run failed jobs\" on the package workflow's run for $TAG \
+(a new workflow_dispatch run does not count), then re-run the AUR Publish job for $TAG."
+
+# Print the basenames of the package workflows found in WORKFLOW_DIR.
+discover() {
+  local f
+  for f in "$WORKFLOW_DIR"/package-*.yml; do
+    [ -e "$f" ] && basename "$f"
+  done
+  return 0
+}
+
+# Print "<status> <conclusion> <html_url>" for the newest push run of TAG at
+# SHA for one workflow, or "none" if there is no such run yet. On an API or
+# parse failure, print the error text and return nonzero.
+latest() {
+  local wf=$1 body
+  if ! body=$(gh api "repos/$GITHUB_REPOSITORY/actions/workflows/$wf/runs?head_sha=$SHA&event=push&per_page=100" 2>"$ERRS"); then
+    tr '\n' ' ' < "$ERRS"
+    return 1
+  fi
+  printf '%s\n' "$body" | jq -er --arg tag "$TAG" --arg sha "$SHA" '
+    [.workflow_runs[]
+      | select(.head_branch == $tag and .head_sha == $sha and .event == "push")]
+    | sort_by(.created_at)
+    | if length == 0 then "none"
+      else last | "\(.status) \(.conclusion // "none") \(.html_url)" end' 2>&1
+}
+
+mapfile -t pending < <(discover)
+if [ "${#pending[@]}" -eq 0 ]; then
+  echo "No package-*.yml workflows found in $WORKFLOW_DIR; refusing to treat an empty set as done" >&2
+  exit 1
+fi
+if [ "${DISCOVER_ONLY:-}" = 1 ]; then
+  printf '%s\n' "${pending[@]}"
+  exit 0
+fi
+
+ERRS=$(mktemp)
+trap 'rm -f "$ERRS"' EXIT
+
+echo "Waiting for $TAG ($SHA) runs of: ${pending[*]}"
+declare -A seen
+for ((poll = 1; poll <= AWAIT_POLLS; poll++)); do
+  still=()
+  for wf in "${pending[@]}"; do
+    if ! state=$(latest "$wf"); then
+      seen[$wf]="API error: $state"
+      still+=("$wf")
+      continue
+    fi
+    seen[$wf]=$state
+    read -r status conclusion url <<< "$state"
+    case "$status" in
+      none)
+        # The tag run has not been created yet.
+        still+=("$wf") ;;
+      completed)
+        if [ "$conclusion" = success ]; then
+          echo "$wf: succeeded ($url)"
+        else
+          echo "$wf: run for $TAG concluded '$conclusion' ($url); not publishing to the AUR" >&2
+          echo "$RECOVERY" >&2
+          exit 1
+        fi ;;
+      *)
+        # queued, in_progress, waiting, requested or pending.
+        still+=("$wf") ;;
+    esac
+  done
+  pending=("${still[@]}")
+  if [ "${#pending[@]}" -eq 0 ]; then
+    echo "Every package workflow run for $TAG has succeeded"
+    exit 0
+  fi
+  echo "Poll $poll/$AWAIT_POLLS: waiting on ${pending[*]}"
+  if [ "$poll" -lt "$AWAIT_POLLS" ]; then sleep "$AWAIT_INTERVAL"; fi
+done
+
+echo "Gave up after $AWAIT_POLLS polls; not publishing to the AUR. Still unfinished:" >&2
+for wf in "${pending[@]}"; do
+  echo "  $wf: ${seen[$wf]}" >&2
+done
+echo "If a run is still going, re-run the AUR Publish job for $TAG once it has succeeded." >&2
+echo "$RECOVERY" >&2
+exit 1
diff --git a/packaging/aur/test-await-package-runs.sh b/packaging/aur/test-await-package-runs.sh
new file mode 100755
index 00000000..42fa2813
--- /dev/null
+++ b/packaging/aur/test-await-package-runs.sh
@@ -0,0 +1,233 @@
+#!/usr/bin/env bash
+# Fixture tests for await-package-runs.sh, the gate that holds the AUR publish
+# until every package workflow run for the release tag has succeeded.
+#
+# Each case writes GitHub API responses into a fixture directory and puts a
+# stub `gh` first on PATH. The stub serves <workflow>.<call>.json for the Nth
+# call about a workflow, falls back to <workflow>.json, and exits 1 when the
+# fixture holds a file named `gh-fails`. It counts calls per workflow so a
+# case can assert that the gate polled again rather than stopping early.
+#
+# Needs bash and jq. Exits nonzero if any case fails or if fewer cases ran
+# than are defined.
+#
+# Usage: bash packaging/aur/test-await-package-runs.sh
+
+set -euo pipefail
+
+HERE=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+GATE="${GATE:-$HERE/await-package-runs.sh}"
+REPO_ROOT=$(cd "$HERE/../.." && pwd)
+
+TAG=v9.9.9
+SHA=0123456789abcdef0123456789abcdef01234567
+WORKFLOWS=(package-freebsd.yml package-linux.yml package-macos.yml
+           package-openwrt.yml package-windows.yml)
+
+WORK=$(mktemp -d)
+trap 'rm -rf "$WORK"' EXIT
+
+# The stub gh. It answers `gh api <url>` only, which is all the gate uses.
+mkdir -p "$WORK/bin"
+cat > "$WORK/bin/gh" <<'STUB'
+#!/usr/bin/env bash
+set -euo pipefail
+[ "${1:-}" = "api" ] || { echo "stub gh: unexpected args: $*" >&2; exit 2; }
+[ -e "$STUB_FIXTURE/gh-fails" ] && { echo "stub gh: simulated API error" >&2; exit 1; }
+wf=$(printf '%s\n' "$2" | sed -E 's|.*/actions/workflows/([^/]+)/runs.*|\1|')
+count_file="$STUB_CALLS/$wf"
+n=$(( $(cat "$count_file" 2>/dev/null || echo 0) + 1 ))
+echo "$n" > "$count_file"
+if [ -f "$STUB_FIXTURE/$wf.$n.json" ]; then
+  cat "$STUB_FIXTURE/$wf.$n.json"
+elif [ -f "$STUB_FIXTURE/$wf.json" ]; then
+  cat "$STUB_FIXTURE/$wf.json"
+else
+  echo '{"total_count":0,"workflow_runs":[]}'
+fi
+STUB
+chmod +x "$WORK/bin/gh"
+
+# A workflow directory holding the five package workflows as empty files: the
+# gate discovers the population by file name only.
+mkdir -p "$WORK/workflows" "$WORK/empty-workflows"
+for wf in "${WORKFLOWS[@]}"; do : > "$WORK/workflows/$wf"; done
+
+# Print one run object in the shape of the v0.5.1 API response.
+# Args: head_branch status conclusion created_at id
+run() {
+  local conclusion=null
+  [ "$3" = null ] || conclusion="\"$3\""
+  printf '{"id":%s,"name":"Package","head_branch":"%s","head_sha":"%s","event":"push","status":"%s","conclusion":%s,"created_at":"%s","updated_at":"%s","html_url":"https://github.com/example/fips/actions/runs/%s"}' \
+    "$5" "$1" "$SHA" "$2" "$conclusion" "$4" "$4" "$5"
+}
+
+# Wrap run objects, given as arguments in the order the API returns them, in
+# the list response envelope.
+runs() {
+  local IFS=,
+  printf '{"total_count":%d,"workflow_runs":[%s]}\n' "$#" "$*"
+}
+
+# Write the healthy v0.5.1 shape for every workflow into a fixture: a tag run
+# and a branch run of the same commit, newest first, both successful.
+all_green() {
+  local dir=$1 wf
+  for wf in "${WORKFLOWS[@]}"; do
+    runs "$(run "$TAG" completed success 2026-09-06T20:31:48Z 2)" \
+         "$(run maint completed success 2026-09-06T20:31:10Z 1)" > "$dir/$wf.json"
+  done
+}
+
+CASES_DEFINED=0
+CASES_RAN=0
+FAILED=0
+
+# Run the gate against a fixture and check its exit status and, when a
+# pattern is given, that its output states the expected reason (so a red
+# caused by a crash in the gate does not pass as the intended red).
+# Args: name fixture-dir expect(zero|nonzero) [pattern] [workflow-dir]
+# Sets LAST_OUT to the gate's combined output.
+check() {
+  local name=$1 fixture=$2 expect=$3 pattern=${4:-} wfdir=${5:-$WORK/workflows} rc=0
+  CASES_RAN=$((CASES_RAN + 1))
+  rm -rf "$WORK/calls"; mkdir -p "$WORK/calls"
+  LAST_OUT=$(PATH="$WORK/bin:$PATH" STUB_FIXTURE="$fixture" STUB_CALLS="$WORK/calls" \
+    GITHUB_REPOSITORY=example/fips TAG="$TAG" SHA="$SHA" WORKFLOW_DIR="$wfdir" \
+    AWAIT_POLLS=3 AWAIT_INTERVAL=0 bash "$GATE" 2>&1) || rc=$?
+  if { [ "$expect" = zero ] && [ "$rc" -eq 0 ]; } ||
+     { [ "$expect" = nonzero ] && [ "$rc" -ne 0 ]; }; then
+    if [ -z "$pattern" ] || printf '%s\n' "$LAST_OUT" | grep -qE -- "$pattern"; then
+      echo "PASS $name (exit $rc)"
+      return 0
+    fi
+    echo "FAIL $name: exit $rc as expected, but output lacks /$pattern/"
+  else
+    echo "FAIL $name: expected $expect exit, got $rc"
+  fi
+  printf '%s\n' "$LAST_OUT" | sed 's/^/    /'
+  FAILED=$((FAILED + 1))
+  return 1
+}
+
+# Record an extra assertion's failure against the case that just ran.
+fail() {
+  echo "FAIL $1"
+  FAILED=$((FAILED + 1))
+}
+
+# Make a fresh fixture directory for a case and print its path.
+fixture() {
+  local dir="$WORK/fx/$1"
+  mkdir -p "$dir"
+  echo "$dir"
+}
+
+# --- cases -------------------------------------------------------------------
+
+# 1: every package workflow has a successful tag run.
+CASES_DEFINED=$((CASES_DEFINED + 1))
+fx=$(fixture 1); all_green "$fx"
+check "1 all tag runs succeeded" "$fx" zero "has succeeded$" || true
+
+# 2: one tag run failed; the gate must name that workflow.
+CASES_DEFINED=$((CASES_DEFINED + 1))
+fx=$(fixture 2); all_green "$fx"
+runs "$(run "$TAG" completed failure 2026-09-06T20:31:48Z 2)" \
+     "$(run maint completed success 2026-09-06T20:31:10Z 1)" > "$fx/package-macos.yml.json"
+if check "2 one tag run failed" "$fx" nonzero "concluded 'failure'"; then
+  printf '%s\n' "$LAST_OUT" | grep -q 'package-macos.yml' ||
+    fail "2 one tag run failed: output does not name package-macos.yml"
+fi
+
+# 3: one tag run was cancelled.
+CASES_DEFINED=$((CASES_DEFINED + 1))
+fx=$(fixture 3); all_green "$fx"
+runs "$(run "$TAG" completed cancelled 2026-09-06T20:31:48Z 2)" > "$fx/package-openwrt.yml.json"
+check "3 one tag run cancelled" "$fx" nonzero "package-openwrt.yml: run for .* concluded 'cancelled'" || true
+
+# 4: one workflow has only the branch run of the tag's commit (the v0.5.1
+# shape a SHA-only filter would accept).
+CASES_DEFINED=$((CASES_DEFINED + 1))
+fx=$(fixture 4); all_green "$fx"
+runs "$(run maint completed success 2026-09-06T20:31:10Z 1)" > "$fx/package-freebsd.yml.json"
+check "4 only a branch run, no tag run" "$fx" nonzero "package-freebsd.yml: none$" || true
+
+# 5: one tag run is in progress on the first poll and succeeds on the second.
+CASES_DEFINED=$((CASES_DEFINED + 1))
+fx=$(fixture 5); all_green "$fx"
+runs "$(run "$TAG" in_progress null 2026-09-06T20:31:48Z 2)" > "$fx/package-freebsd.yml.1.json"
+if check "5 in progress, then succeeded" "$fx" zero "has succeeded$"; then
+  calls=$(cat "$WORK/calls/package-freebsd.yml" 2>/dev/null || echo 0)
+  [ "$calls" -ge 2 ] ||
+    fail "5 in progress, then succeeded: gate queried package-freebsd.yml $calls time(s), expected at least 2"
+fi
+
+# 6: one tag run stays in progress for the whole budget.
+CASES_DEFINED=$((CASES_DEFINED + 1))
+fx=$(fixture 6); all_green "$fx"
+runs "$(run "$TAG" in_progress null 2026-09-06T20:31:48Z 2)" > "$fx/package-freebsd.yml.json"
+check "6 in progress for the whole budget" "$fx" nonzero "package-freebsd.yml: in_progress " || true
+
+# 7: no package workflows discovered.
+CASES_DEFINED=$((CASES_DEFINED + 1))
+fx=$(fixture 7); all_green "$fx"
+check "7 empty workflow population" "$fx" nonzero "No package-\*\.yml workflows found" \
+  "$WORK/empty-workflows" || true
+
+# 8a-8d: the tag was re-pushed at the same commit, so two tag runs exist. The
+# newest decides. The API lists newest first; 8b and 8c list oldest first so
+# that "take the first match" and "take the newest" disagree.
+CASES_DEFINED=$((CASES_DEFINED + 1))
+fx=$(fixture 8a); all_green "$fx"
+runs "$(run "$TAG" completed success 2026-09-06T21:00:00Z 3)" \
+     "$(run "$TAG" completed failure 2026-09-06T20:31:48Z 2)" > "$fx/package-linux.yml.json"
+check "8a older failure, newer success, newest first" "$fx" zero "has succeeded$" || true
+
+CASES_DEFINED=$((CASES_DEFINED + 1))
+fx=$(fixture 8b); all_green "$fx"
+runs "$(run "$TAG" completed success 2026-09-06T20:31:48Z 2)" \
+     "$(run "$TAG" completed failure 2026-09-06T21:00:00Z 3)" > "$fx/package-linux.yml.json"
+check "8b older success, newer failure, oldest first" "$fx" nonzero \
+  "package-linux.yml: run for .* concluded 'failure'" || true
+
+CASES_DEFINED=$((CASES_DEFINED + 1))
+fx=$(fixture 8c); all_green "$fx"
+runs "$(run "$TAG" completed failure 2026-09-06T20:31:48Z 2)" \
+     "$(run "$TAG" completed success 2026-09-06T21:00:00Z 3)" > "$fx/package-linux.yml.json"
+check "8c older failure, newer success, oldest first" "$fx" zero "has succeeded$" || true
+
+CASES_DEFINED=$((CASES_DEFINED + 1))
+fx=$(fixture 8d); all_green "$fx"
+runs "$(run "$TAG" completed failure 2026-09-06T21:00:00Z 3)" \
+     "$(run "$TAG" completed success 2026-09-06T20:31:48Z 2)" > "$fx/package-linux.yml.json"
+check "8d older success, newer failure, newest first" "$fx" nonzero \
+  "package-linux.yml: run for .* concluded 'failure'" || true
+
+# 9: every API call fails.
+CASES_DEFINED=$((CASES_DEFINED + 1))
+fx=$(fixture 9); all_green "$fx"; : > "$fx/gh-fails"
+check "9 gh fails on every call" "$fx" nonzero "package-linux.yml: API error" || true
+
+# 10: discovery against the repository's real workflow directory.
+CASES_DEFINED=$((CASES_DEFINED + 1))
+CASES_RAN=$((CASES_RAN + 1))
+rc=0
+found=$(DISCOVER_ONLY=1 WORKFLOW_DIR="$REPO_ROOT/.github/workflows" \
+  GITHUB_REPOSITORY=example/fips TAG="$TAG" SHA="$SHA" bash "$GATE" 2>&1) || rc=$?
+if [ "$rc" -eq 0 ] && [ -n "$found" ] &&
+   printf '%s\n' "$found" | grep -qx 'package-linux.yml'; then
+  echo "PASS 10 real workflow discovery: $(printf '%s\n' "$found" | tr '\n' ' ')"
+else
+  echo "FAIL 10 real workflow discovery: exit $rc, found: $found"
+  FAILED=$((FAILED + 1))
+fi
+
+# -----------------------------------------------------------------------------
+
+echo "cases defined: $CASES_DEFINED, ran: $CASES_RAN, failed: $FAILED"
+if [ "$CASES_RAN" -ne "$CASES_DEFINED" ]; then
+  echo "FAIL: not every defined case ran"
+  exit 1
+fi
+[ "$FAILED" -eq 0 ]
diff --git a/testing/interop/README.md b/testing/interop/README.md
index c87cb319..a481bd0b 100644
--- a/testing/interop/README.md
+++ b/testing/interop/README.md
@@ -177,12 +177,17 @@ FIPS_INTEROP_NETEM="delay 10ms 5ms 25% loss 2%" \
   wants netem) but still runs a clean baseline loop.
 
 Each rep invokes `interop-test.sh` with netem set and captures its full
-output and exit code; a rep passes iff `interop-test.sh` exits 0. Artifacts
-land in `testing/interop/.stress-runs/<UTC-timestamp>/`:
+output and exit code; a rep passes iff `interop-test.sh` exits 0. Every rep
+runs with `FIPS_INTEROP_KEEP_UP=1`, because whether it failed is known only
+after the driver exits: the loop saves a failed rep's per-node logs and then
+tears the mesh down itself, including when the loop is interrupted.
+Artifacts land in `testing/interop/.stress-runs/<UTC-timestamp>/`:
 
 - `rep-NN/driver.log` — full driver output for every rep.
 - `rep-NN/docker-<container>.log` — per-container `docker logs` for **failed**
-  reps only.
+  reps only. The expected containers come from the generated manifest, and
+  the loop prints `harvest: k of n per-node logs written` for each failed
+  rep. A log that could not be read or came back empty counts as missing.
 - `summary.txt` — the aggregate report.
 
 The aggregate report gives reps run, passed/failed counts and an integer
@@ -193,9 +198,10 @@ pair kind (mixed vs same), and a verdict:
 - **both mixed and same pairs** → loss-induced general instability;
 - **same-version control pair only** → the build is unstable against itself.
 
-`interop-stress.sh` exits **non-zero only** for the interop-regression
-signal. A sub-100% pass rate under loss is expected and is not by itself a
-failure, so every other outcome exits 0.
+`interop-stress.sh` exits **1** for the interop-regression signal and **3**
+when a failed rep's per-node logs are incomplete (the run's diagnostics are
+missing; a regression keeps exit 1). A sub-100% pass rate under loss is
+expected and is not by itself a failure, so every other outcome exits 0.
 
 ### Options
 
@@ -203,7 +209,8 @@ failure, so every other outcome exits 0.
 | ---------------------------- | ------------------------------------------------- |
 | `FIPS_INTEROP_NETEM`         | tc-netem string applied to each container's eth0, e.g. `"delay 10ms 5ms 25% loss 1%"`. Passed through `interop-stress.sh` to `interop-test.sh`. |
 | `REKEY_AFTER_SECS`           | Rekey interval for generated configs (default 35).|
-| `FIPS_INTEROP_KEEP_UP`       | `1` = leave containers running after the test.    |
+| `CONTROL_MAX_ATTEMPTS`       | Control windows Phase 1b measures before Phase 5b abstains (default 3). |
+| `FIPS_INTEROP_KEEP_UP`       | `1` = leave containers running after the test. The stress loop sets it for every rep and tears down itself. |
 | `FIPS_INTEROP_KEEP_WORKTREES`| `1` = keep `build-images.sh` worktrees (debug).   |
 | `FIPS_INTEROP_RUNS_DIR`      | Root for the three scratch dirs — see [Scratch directory location](#scratch-directory-location). |
 
@@ -249,6 +256,16 @@ The driver runs seven phases:
 | 5     | All pairs still ping after the second rekey.                     |
 | 6     | Per-node / per-pair interop log analysis.                        |
 
+When data-plane streams are on (`--topology`, or `FIPS_INTEROP_STREAMS`),
+Phase 1b measures stream loss over a quiet control window and Phase 5b
+compares the loss across the rekey window against it. A control window
+counts only if no FMP rekey cutover happened during it and the cutover
+count could be read on every node. Otherwise Phase 1b waits for the
+cutovers to settle and re-measures, up to `CONTROL_MAX_ATTEMPTS` times (default
+3). If no attempt is clean, Phase 5b prints `ABSTAIN` for every stream and
+returns no verdict, and the summary says so. The stress loop reports in how
+many reps Phase 5b abstained and in how many it re-measured.
+
 Phase 6 is the interop-specific part. It reports:
 
 - **Global health** — panics, `ERROR` lines, `unknown FMP version` drops,
diff --git a/testing/interop/interop-stress.sh b/testing/interop/interop-stress.sh
index 6cf98952..933da670 100755
--- a/testing/interop/interop-stress.sh
+++ b/testing/interop/interop-stress.sh
@@ -19,8 +19,13 @@
 #         -> the version under test is unstable even against itself.
 #
 # A sub-100% pass rate under loss is EXPECTED and is not, by itself, a
-# failure. This script exits non-zero ONLY for the interop-regression
-# signal (mixed-only failures).
+# failure. This script exits 1 for the interop-regression signal
+# (mixed-only failures) and 3 when a failed rep's per-node logs could not
+# all be saved, so its diagnostics are incomplete.
+#
+# Every rep runs with FIPS_INTEROP_KEEP_UP=1, because whether a rep failed
+# is known only after the driver exits. The loop saves a failed rep's
+# per-node logs and then tears the mesh down itself.
 #
 # Reps run SERIALLY — interop-test.sh uses fixed container names and a
 # fixed Docker network, so two reps must never overlap.
@@ -52,7 +57,10 @@
 #
 # Artifacts (per invocation): <runs-base>/.stress-runs/<UTC-ts>/
 #   rep-NN/driver.log        full interop-test.sh output for that rep.
-#   rep-NN/docker-<node>.log per-container `docker logs` (FAILED reps only).
+#   rep-NN/docker-<container>.log
+#                            per-container `docker logs` (FAILED reps only).
+#                            A failed rep with fewer of these than nodes
+#                            makes the run exit 3.
 #   summary.txt              the final aggregate report.
 
 set -uo pipefail
@@ -80,6 +88,65 @@ else
 fi
 
 RUNS_BASE="$INTEROP_RUNS_BASE/.stress-runs"
+# The driver's generated mesh (same paths as interop-test.sh), read for the
+# expected container set and used to tear a kept-up rep down.
+GEN_DIR="$INTEROP_RUNS_BASE/generated-configs"
+COMPOSE_FILE="$GEN_DIR/docker-compose.generated.yml"
+NODES_ENV="$GEN_DIR/nodes.env"
+
+# Save every node's `docker logs` into a failed rep's directory.
+#
+# The expected containers come from the generated manifest rather than
+# from `docker ps`: an empty `docker ps` result is how a harvest that saved
+# nothing used to pass without a word. A container counts only when
+# `docker logs` succeeded and wrote a non-empty file. Returns 0 only when
+# every expected container was saved and there was at least one.
+harvest_rep() {
+    local rep_dir="$1" containers tok ctr n=0 k=0
+    local missing=()
+    # A subshell, so the manifest's variables stay out of the loop.
+    # shellcheck disable=SC1090
+    containers="$( [ -f "$NODES_ENV" ] && . "$NODES_ENV" \
+        && printf '%s' "${INTEROP_NODE_CONTAINERS:-}" )" || containers=""
+    for tok in $containers; do
+        ctr="${tok#*:}"
+        n=$((n + 1))
+        if docker logs "$ctr" >"$rep_dir/docker-$ctr.log" 2>&1 \
+            && [ -s "$rep_dir/docker-$ctr.log" ]; then
+            k=$((k + 1))
+        else
+            missing+=("$ctr")
+        fi
+    done
+    echo "       harvest: $k of $n per-node logs written"
+    if [ "$n" -eq 0 ]; then
+        echo "       HARVEST FAILED: no manifest / empty container list ($NODES_ENV)"
+        return 1
+    fi
+    if [ "$k" -lt "$n" ]; then
+        echo "       HARVEST FAILED: $k of $n; missing: ${missing[*]}"
+        return 1
+    fi
+    return 0
+}
+
+# Tear down a rep's kept-up mesh. A failure is loud but not fatal: the
+# next rep's Phase 0 also brings the mesh down before starting.
+teardown_rep() {
+    local rc left
+    docker compose -f "$COMPOSE_FILE" down --volumes --remove-orphans \
+        >/dev/null 2>&1
+    rc=$?
+    MESH_UP=0
+    if [ "$rc" -ne 0 ]; then
+        echo "       WARN: teardown failed ($rc)"
+    fi
+    left="$(docker ps -a --filter 'name=fips-interop-' --format '{{.Names}}' 2>/dev/null)"
+    if [ -n "$left" ]; then
+        echo "       WARN: containers remain after teardown: $(echo "$left" | tr '\n' ' ')"
+    fi
+    return "$rc"
+}
 
 # ── Args ─────────────────────────────────────────────────────────────
 
@@ -171,6 +238,13 @@ RUN_TS="$(date -u +%Y-%m-%dT%H-%M-%SZ)"
 RUN_DIR="$RUNS_BASE/$RUN_TS"
 mkdir -p "$RUN_DIR"
 
+# A rep runs kept up, so an interrupted or aborted loop must still take
+# its mesh down. The INT and TERM traps exit, which runs the EXIT trap.
+MESH_UP=0
+trap '[ "$MESH_UP" -eq 1 ] && teardown_rep' EXIT
+trap 'echo ""; echo "Interrupted"; exit 130' INT
+trap 'echo ""; echo "Terminated"; exit 143' TERM
+
 echo "=============================================================="
 echo " FIPS Interop Netem Stress Loop"
 echo "=============================================================="
@@ -186,6 +260,14 @@ echo ""
 PASS_COUNT=0
 FAIL_COUNT=0
 FAILED_REPS=()
+# Failed reps whose per-node logs were not all saved.
+HARVEST_FAILS=0
+HARVEST_FAILED_REPS=()
+# Phase 5b outcomes over the reps that measured a control window (Phase
+# 1b ran): reps that abstained, and reps that re-measured at least once.
+STREAM_REPS=0
+ABSTAIN_REPS=0
+REMEASURE_REPS=0
 # Per-kind connectivity-failure tallies, summed across all failed reps.
 MIXED_FAILS=0
 SAME_FAILS=0
@@ -199,11 +281,27 @@ for ((rep = 1; rep <= REPS; rep++)); do
     echo "── $rep_id / $REPS ──────────────────────────────────────────"
 
     # Run the driver, capturing full output and exit code. Netem is
-    # passed through the environment; interop-test.sh applies it.
-    FIPS_INTEROP_NETEM="${FIPS_INTEROP_NETEM:-}" \
+    # passed through the environment; interop-test.sh applies it. The
+    # mesh is kept up so a failed rep can be harvested below.
+    MESH_UP=1
+    FIPS_INTEROP_KEEP_UP=1 FIPS_INTEROP_NETEM="${FIPS_INTEROP_NETEM:-}" \
         bash "$DRIVER" "${DRIVER_ARGS[@]}" >"$driver_log" 2>&1
     rc=$?
 
+    # Tallied for every rep whatever its verdict: abstaining is the absence
+    # of a verdict rather than a failure, so without this count a run whose
+    # Phase 5b always abstains would pass unnoticed.
+    if grep -q '^Phase 1b: ' "$driver_log"; then
+        STREAM_REPS=$((STREAM_REPS + 1))
+        if grep -q '^  ABSTAIN  Data-plane continuity' "$driver_log"; then
+            ABSTAIN_REPS=$((ABSTAIN_REPS + 1))
+            echo "  Phase 5b abstained (no clean control window)"
+        fi
+        if grep -q 'control window attempt .*re-measuring' "$driver_log"; then
+            REMEASURE_REPS=$((REMEASURE_REPS + 1))
+        fi
+    fi
+
     if [ "$rc" -eq 0 ]; then
         PASS_COUNT=$((PASS_COUNT + 1))
         echo "  PASS (exit 0)"
@@ -212,14 +310,11 @@ for ((rep = 1; rep <= REPS; rep++)); do
         FAILED_REPS+=("$rep_id")
         echo "  FAIL (exit $rc)"
 
-        # Preserve each failed container's full docker logs. The driver
-        # uses fixed container names fips-interop-<nodeid>; harvest every
-        # container matching that prefix that still exists.
-        while read -r ctr; do
-            [ -n "$ctr" ] || continue
-            docker logs "$ctr" >"$rep_dir/docker-${ctr}.log" 2>&1 || true
-        done < <(docker ps -a --filter 'name=fips-interop-' \
-                    --format '{{.Names}}' 2>/dev/null)
+        # Preserve each node's full docker logs before the teardown below.
+        if ! harvest_rep "$rep_dir"; then
+            HARVEST_FAILS=$((HARVEST_FAILS + 1))
+            HARVEST_FAILED_REPS+=("$rep_id")
+        fi
 
         # Tally connectivity failures by pair kind, reusing the
         # pair-attributed lines interop-test.sh prints. Each line is
@@ -230,6 +325,8 @@ for ((rep = 1; rep <= REPS; rep++)); do
         SAME_FAILS=$((SAME_FAILS + s))
         echo "       connectivity-failure lines: mixed=$m same=$s"
     fi
+
+    teardown_rep
 done
 
 echo ""
@@ -285,6 +382,10 @@ else
     VERDICT="NO connectivity-pair failures recorded, but $FAIL_COUNT rep(s) still"
     VERDICT2="failed — on non-connectivity signatures (global-health log patterns or a missing rekey). Check the per-rep driver logs."
 fi
+# A regression keeps precedence; otherwise missing diagnostics fail the run.
+if [ "$EXIT_CODE" -eq 0 ] && [ "$HARVEST_FAILS" -gt 0 ]; then
+    EXIT_CODE=3
+fi
 
 {
     echo "=============================================================="
@@ -302,6 +403,12 @@ fi
     if [ "${#FAILED_REPS[@]}" -gt 0 ]; then
         echo "Failed reps: ${FAILED_REPS[*]}"
     fi
+    if [ "$HARVEST_FAILS" -gt 0 ]; then
+        echo "Harvest    : $HARVEST_FAILS failed rep(s) with incomplete per-node logs: ${HARVEST_FAILED_REPS[*]}"
+    fi
+    if [ "$STREAM_REPS" -gt 0 ]; then
+        echo "Phase 5b   : abstained in $ABSTAIN_REPS of $STREAM_REPS reps; re-measured in $REMEASURE_REPS of $STREAM_REPS reps"
+    fi
     echo ""
     echo "-- Connectivity-failure attribution (summed over failed reps) --"
     echo "  mixed-version : $MIXED_FAILS failure(s) over $MIXED_PAIRS mixed pairs x $REPS reps"
@@ -315,6 +422,9 @@ fi
     if [ "$EXIT_CODE" -eq 0 ]; then
         echo "Exit 0: no interop-regression signal (a sub-100% rate under loss"
         echo "        is expected and is not by itself a failure)."
+    elif [ "$EXIT_CODE" -eq 3 ]; then
+        echo "Exit 3: per-node logs missing for a failed rep; the run's"
+        echo "        diagnostics are incomplete."
     else
         echo "Exit 1: interop-regression signal present."
     fi
diff --git a/testing/interop/interop-test.sh b/testing/interop/interop-test.sh
index 3d8e41dd..913518fe 100755
--- a/testing/interop/interop-test.sh
+++ b/testing/interop/interop-test.sh
@@ -53,6 +53,9 @@
 #                          by --topology; empty = streams off.
 #   STREAM_LOSS_MARGIN_PCT rekey-vs-control loss margin (default 5).
 #   CONTROL_STREAM_SECS    quiet control-window length (default 12).
+#   CONTROL_MAX_ATTEMPTS   control windows measured before Phase 5b
+#                          abstains because every one saw a rekey
+#                          cutover or could not be checked (default 3).
 #   MESH_SIZE_WARMUP       Phase 7 bloom warmup, from mesh start, before
 #                          any estimate counts (default 300).
 #   MESH_SIZE_SETTLE       Phase 7 unbroken in-band window a node must
@@ -190,6 +193,14 @@ LOG_POLL_INTERVAL=2
 # as on mixed ones.
 STREAM_RATE_HZ=20
 CONTROL_STREAM_SECS="${CONTROL_STREAM_SECS:-12}" # quiet pre-rekey window
+# A control window that saw a rekey cutover, or whose cutover count could
+# not be read, is no baseline. Phase 1b re-measures it, after waiting for
+# the cutover count to hold still for CONTROL_QUIET_SECS (at most
+# CONTROL_QUIET_MAX) so the retry does not land in the same cluster of
+# cutovers, and Phase 5b abstains when no attempt comes out clean.
+CONTROL_MAX_ATTEMPTS="${CONTROL_MAX_ATTEMPTS:-3}"
+CONTROL_QUIET_SECS=5
+CONTROL_QUIET_MAX=30
 # 5% is 12 packets of the 240-packet control window and ~155 of the
 # ~3100-packet rekey window. On a path losing up to 6% (the range the
 # v0.4.2 netem runs baselined at, under `loss 2%` over several hops) the
@@ -526,6 +537,37 @@ count_log_pattern() {
     return 0
 }
 
+# Count completed FMP initiator rekey cutovers across all node logs.
+#
+# The pattern is a literal argument so the log-string guard can check it
+# against the daemon source. Prints the count, or `unreadable:<ctr>` with
+# status 1 when a node's logs cannot be read.
+fmp_cutover_count() {
+    count_log_pattern 'Rekey cutover complete \(initiator\), K-bit flipped'
+    return $?
+}
+
+# Wait until the FMP cutover count has held unchanged for
+# CONTROL_QUIET_SECS, giving up after CONTROL_QUIET_MAX. An unreadable
+# count is treated as a change, so it never counts as quiet.
+wait_cutover_quiet() {
+    local start=$SECONDS still=$SECONDS last cur
+    last="$(fmp_cutover_count)" || last="unreadable"
+    while (( SECONDS - still < CONTROL_QUIET_SECS )); do
+        if (( SECONDS - start >= CONTROL_QUIET_MAX )); then
+            echo "    cutover count still moving after ${CONTROL_QUIET_MAX}s; measuring anyway"
+            return 1
+        fi
+        sleep 1
+        cur="$(fmp_cutover_count)" || cur="unreadable"
+        if [ "$cur" != "$last" ] || [ "$cur" = "unreadable" ]; then
+            last="$cur"
+            still=$SECONDS
+        fi
+    done
+    return 0
+}
+
 # Per-node count of a pattern.
 count_node_pattern() {
     local node="$1" pattern="$2"
@@ -765,25 +807,52 @@ echo ""
 # ── Phase 1b: data-plane control window (quiet, pre-rekey) ───────────
 #
 # Measure stream loss over a window with NO rekey cutover, as the control
-# baseline for the differential. Validated cutover-free by confirming the
-# FMP cutover count did not advance during the window. Then launch the
+# baseline for the differential. A window counts only when the FMP cutover
+# count was read before and after it and did not advance. A window that
+# saw a cutover, or could not be checked, is re-measured up to
+# CONTROL_MAX_ATTEMPTS times; if none is clean, Phase 5b abstains rather
+# than computing a verdict from a contaminated baseline. Then launch the
 # rekey-window streams, which run in the background across Phases 2-5 and
 # are collected/asserted in Phase 5b.
-control_contaminated=0
+control_abstain=0
 if [ "${#STREAM_PAIRS[@]}" -gt 0 ]; then
-    echo "Phase 1b: Data-plane control stream (${CONTROL_STREAM_SECS}s quiet window)"
-    pre_cut="$(count_log_pattern 'Rekey cutover complete \(initiator\), K-bit flipped')"
-    launch_streams CONTROL "$CONTROL_STREAM_SECS"
-    collect_streams
-    post_cut="$(count_log_pattern 'Rekey cutover complete \(initiator\), K-bit flipped')"
-    if [ "$post_cut" -ne "$pre_cut" ]; then
-        control_contaminated=1
-        echo "  WARN  a rekey cutover occurred during the control window — control loss may be contaminated"
+    echo "Phase 1b: Data-plane control stream (${CONTROL_STREAM_SECS}s quiet window, up to ${CONTROL_MAX_ATTEMPTS} attempts)"
+    control_ok=0
+    for ((attempt = 1; attempt <= CONTROL_MAX_ATTEMPTS; attempt++)); do
+        pre_rc=0
+        post_rc=0
+        pre_cut="$(fmp_cutover_count)" || pre_rc=$?
+        launch_streams CONTROL "$CONTROL_STREAM_SECS"
+        collect_streams
+        post_cut="$(fmp_cutover_count)" || post_rc=$?
+        if [ "$pre_rc" -ne 0 ] || ! [[ "$pre_cut" =~ ^[0-9]+$ ]]; then
+            why="cutover count unreadable ($pre_cut)"
+        elif [ "$post_rc" -ne 0 ] || ! [[ "$post_cut" =~ ^[0-9]+$ ]]; then
+            why="cutover count unreadable ($post_cut)"
+        elif [ "$post_cut" -ne "$pre_cut" ]; then
+            why="a rekey cutover occurred (+$((post_cut - pre_cut)))"
+        else
+            control_ok=1
+            echo "  control window accepted on attempt $attempt/$CONTROL_MAX_ATTEMPTS"
+            break
+        fi
+        if [ "$attempt" -lt "$CONTROL_MAX_ATTEMPTS" ]; then
+            echo "  control window attempt $attempt/$CONTROL_MAX_ATTEMPTS: $why; re-measuring"
+            wait_cutover_quiet || true
+        else
+            echo "  control window attempt $attempt/$CONTROL_MAX_ATTEMPTS: $why"
+        fi
+    done
+    if [ "$control_ok" -eq 0 ]; then
+        control_abstain=1
+        echo "  ABSTAIN  control window contaminated on all $CONTROL_MAX_ATTEMPTS attempts; Phase 5b will not return a verdict"
     fi
+    ctl_note=""
+    [ "$control_abstain" -eq 1 ] && ctl_note=" (last attempt, contaminated)"
     for sp in "${STREAM_PAIRS[@]}"; do
         read -r sf st <<< "$sp"
         key="$sf->$st"
-        echo "    control $key: tx=${STREAM_TX[CONTROL:$key]:-0} rx=${STREAM_RX[CONTROL:$key]:-0} loss=$(_loss_pct "${STREAM_TX[CONTROL:$key]:-0}" "${STREAM_RX[CONTROL:$key]:-0}")%"
+        echo "    control $key: tx=${STREAM_TX[CONTROL:$key]:-0} rx=${STREAM_RX[CONTROL:$key]:-0} loss=$(_loss_pct "${STREAM_TX[CONTROL:$key]:-0}" "${STREAM_RX[CONTROL:$key]:-0}")%$ctl_note"
     done
     echo "  Launching rekey-window streams (${REKEY_STREAM_SECS}s, spanning Phases 2-5)"
     launch_streams REKEY "$REKEY_STREAM_SECS"
@@ -863,6 +932,12 @@ if [ "${#STREAM_PAIRS[@]}" -gt 0 ]; then
             if (k <= c + m) print "PASS"; else print "FAIL"
         }')"
         delta="$(awk -v c="$cpct" -v k="$rpct" 'BEGIN{ if(c=="NA"||k=="NA") print "NA"; else printf "%+.1f", k-c }')"
+        # No clean control window: report the losses for reading, but
+        # compute no verdict from a contaminated baseline.
+        if [ "$control_abstain" -eq 1 ]; then
+            printf '    %-16s %11s %11s %8s  %s\n' "$key" "$cpct" "$rpct" "$delta" "ABSTAIN"
+            continue
+        fi
         printf '    %-16s %11s %11s %8s  %s\n' "$key" "$cpct" "$rpct" "$delta" "$verdict"
         if [ "$verdict" = "PASS" ]; then
             PASSED=$((PASSED + 1))
@@ -871,8 +946,11 @@ if [ "${#STREAM_PAIRS[@]}" -gt 0 ]; then
             INTEROP_FAILURES+=("[stream] $key ($(hop_label "$sf" "$st")): rekey-window loss ${rpct}% vs control ${cpct}% (+${STREAM_LOSS_MARGIN_PCT}% margin) -> $verdict")
         fi
     done
-    [ "${control_contaminated:-0}" -eq 1 ] && echo "    NOTE: control window saw a cutover; differential may understate rekey loss."
-    phase_result "Data-plane continuity across rekey"
+    if [ "$control_abstain" -eq 1 ]; then
+        echo "  ABSTAIN  Data-plane continuity across rekey: no uncontaminated control window in $CONTROL_MAX_ATTEMPTS attempts"
+    else
+        phase_result "Data-plane continuity across rekey"
+    fi
     echo ""
 fi
 
@@ -1078,6 +1156,13 @@ echo "=============================================================="
 # `${#arr[@]}` cannot be combined with `:-`; count into a plain var.
 INTEROP_FAILURE_COUNT="${#INTEROP_FAILURES[@]}"
 
+# An abstaining Phase 5b adds no check, so say so: otherwise a green run
+# reads as having covered data-plane continuity across rekey.
+if [ "${control_abstain:-0}" -eq 1 ]; then
+    echo ""
+    echo "NOTE: Phase 5b abstained (control window contaminated); its rekey-loss check did not run."
+fi
+
 if [ "$TOTAL_FAILED" -eq 0 ] && [ "$INTEROP_FAILURE_COUNT" -eq 0 ]; then
     echo ""
     echo "PASS: all versions interoperate cleanly across the mesh (spec '$SPEC_STR')."