diff --git a/scripts/boot/5g-dial.sh b/scripts/boot/5g-dial.sh
index 1801794..714670f 100644
--- a/scripts/boot/5g-dial.sh
+++ b/scripts/boot/5g-dial.sh
@@ -7,6 +7,40 @@ source "${SCRIPT_DIR}/common.sh"
 
 STEP="5g-dial"
 
+disable_interfaces() {
+  local raw_list="$1"
+  local iface
+  local nmcli_available=0
+
+  if [[ -z "${raw_list}" ]]; then
+    return 0
+  fi
+  if command -v nmcli >/dev/null 2>&1; then
+    nmcli_available=1
+  fi
+
+  for iface in ${raw_list//,/ }; do
+    if [[ -z "${iface}" ]]; then
+      continue
+    fi
+    blitz_log "${STEP}" "disable-interface" "start" "iface=${iface}" 0
+    if [[ "${nmcli_available}" -eq 1 ]]; then
+      nmcli device disconnect "${iface}" >/dev/null 2>&1 || true
+    fi
+    if ip link show dev "${iface}" >/dev/null 2>&1; then
+      if ip link set dev "${iface}" down; then
+        blitz_log "${STEP}" "disable-interface" "success" "iface=${iface}" 0
+      else
+        rc=$?
+        blitz_log "${STEP}" "disable-interface" "failure" "iface=${iface}" "${rc}"
+        return "${rc}"
+      fi
+    else
+      blitz_log "${STEP}" "disable-interface" "success" "iface=${iface} not present, skipping" 0
+    fi
+  done
+}
+
 wait_for_serial() {
   local serial_port="$1"
   local timeout_sec="$2"
@@ -31,23 +65,24 @@ wait_for_serial() {
 wait_for_route() {
   local target_ip="$1"
   local timeout_sec="$2"
+  local expected_interface="${3:-}"
   local waited=0
   local route_output
 
   while (( waited < timeout_sec )); do
-    route_output="$(blitz_route_ready "${target_ip}" || true)"
+    route_output="$(blitz_route_ready "${target_ip}" "${expected_interface}" || true)"
     if [[ -n "${route_output}" ]]; then
-      blitz_log "${STEP}" "route-check" "success" "target_ip=${target_ip} route=${route_output}" 0
+      blitz_log "${STEP}" "route-check" "success" "target_ip=${target_ip} interface=${expected_interface:-auto} route=${route_output}" 0
       return 0
     fi
     if (( waited == 0 || waited % 5 == 0 )); then
-      blitz_log "${STEP}" "route-check" "waiting" "target_ip=${target_ip} waited_sec=${waited}" 0
+      blitz_log "${STEP}" "route-check" "waiting" "target_ip=${target_ip} interface=${expected_interface:-auto} waited_sec=${waited}" 0
     fi
     sleep 1
     waited=$(( waited + 1 ))
   done
 
-  blitz_log "${STEP}" "route-check" "failure" "target_ip=${target_ip} timeout_sec=${timeout_sec}" 1
+  blitz_log "${STEP}" "route-check" "failure" "target_ip=${target_ip} interface=${expected_interface:-auto} timeout_sec=${timeout_sec}" 1
   return 1
 }
 
@@ -61,18 +96,24 @@ if [[ -z "${BLITZ_TIME_SERVER_IP}" ]]; then
   blitz_log "${STEP}" "precheck" "failure" "BLITZ_TIME_SERVER_IP is empty and no fallback could be derived" 1
   exit 1
 fi
+if [[ -z "${BLITZ_5G_INTERFACE:-}" ]]; then
+  blitz_log "${STEP}" "precheck" "failure" "BLITZ_5G_INTERFACE must not be empty" 1
+  exit 1
+fi
 
-route_output="$(blitz_route_ready "${BLITZ_TIME_SERVER_IP}" || true)"
+disable_interfaces "${BLITZ_5G_DISABLE_INTERFACES:-}"
+
+route_output="$(blitz_route_ready "${BLITZ_TIME_SERVER_IP}" "${BLITZ_5G_INTERFACE}" || true)"
 if [[ -n "${route_output}" ]]; then
-  blitz_log "${STEP}" "dial" "already_up" "target_ip=${BLITZ_TIME_SERVER_IP} route=${route_output}" 0
+  blitz_log "${STEP}" "dial" "already_up" "target_ip=${BLITZ_TIME_SERVER_IP} interface=${BLITZ_5G_INTERFACE} route=${route_output}" 0
   exit 0
 fi
 
 wait_for_serial "${BLITZ_5G_SERIAL_PORT}" "${BLITZ_5G_SERIAL_WAIT_SEC}"
 
 pushd "${BLITZ_5G_DIAL_DIR}" >/dev/null
-blitz_run "${STEP}" "dial" python3 rndis_dial.py --serial-port "${BLITZ_5G_SERIAL_PORT}"
+blitz_run "${STEP}" "dial" python3 rndis_dial.py --serial-port "${BLITZ_5G_SERIAL_PORT}" --interface "${BLITZ_5G_INTERFACE}"
 popd >/dev/null
 
-wait_for_route "${BLITZ_TIME_SERVER_IP}" "${BLITZ_5G_ROUTE_WAIT_SEC}"
-blitz_log "${STEP}" "complete" "success" "5G dial completed and route is ready" 0
+wait_for_route "${BLITZ_TIME_SERVER_IP}" "${BLITZ_5G_ROUTE_WAIT_SEC}" "${BLITZ_5G_INTERFACE}"
+blitz_log "${STEP}" "complete" "success" "5G dial completed and route is ready on ${BLITZ_5G_INTERFACE}" 0
diff --git a/scripts/boot/common.sh b/scripts/boot/common.sh
index 5974a96..8caef70 100644
--- a/scripts/boot/common.sh
+++ b/scripts/boot/common.sh
@@ -54,6 +54,8 @@ blitz_load_boot_env() {
   export BLITZ_LOG_FILE="${BLITZ_LOG_FILE:-/var/log/blitz-robot/startup.log}"
   export BLITZ_5G_DIAL_DIR="${BLITZ_5G_DIAL_DIR:-/home/nvidia/5g-test/5G}"
   export BLITZ_5G_SERIAL_PORT="${BLITZ_5G_SERIAL_PORT:-/dev/ttyUSB7}"
+  export BLITZ_5G_INTERFACE="${BLITZ_5G_INTERFACE:-eth0}"
+  export BLITZ_5G_DISABLE_INTERFACES="${BLITZ_5G_DISABLE_INTERFACES:-}"
   export BLITZ_5G_SERIAL_WAIT_SEC="${BLITZ_5G_SERIAL_WAIT_SEC:-60}"
   export BLITZ_5G_ROUTE_WAIT_SEC="${BLITZ_5G_ROUTE_WAIT_SEC:-30}"
   export BLITZ_TIME_SERVER_IP="${BLITZ_TIME_SERVER_IP:-${default_time_server}}"
@@ -158,21 +160,24 @@ blitz_require_root() {
 blitz_run() {
   local step="$1"
   local action="$2"
+  local rc
   shift 2
 
   blitz_log "${step}" "${action}" "start" "$(blitz_join_cmd "$@")" 0
   if "$@"; then
     blitz_log "${step}" "${action}" "success" "$(blitz_join_cmd "$@")" 0
     return 0
+  else
+    rc=$?
   fi
 
-  local rc=$?
   blitz_log "${step}" "${action}" "failure" "$(blitz_join_cmd "$@")" "${rc}"
   return "${rc}"
 }
 
 blitz_route_ready() {
   local target_ip="$1"
+  local expected_interface="${2:-}"
   local route_output
 
   route_output="$(ip route get "${target_ip}" 2>&1 || true)"
@@ -182,6 +187,9 @@ blitz_route_ready() {
   if [[ "${route_output}" == *"unreachable"* || "${route_output}" == *"prohibit"* ]]; then
     return 1
   fi
+  if [[ -n "${expected_interface}" && "${route_output}" != *" dev ${expected_interface} "* && "${route_output}" != *" dev ${expected_interface}" ]]; then
+    return 1
+  fi
 
   printf '%s\n' "${route_output}"
   return 0
diff --git a/scripts/boot/robot-boot.env b/scripts/boot/robot-boot.env
index 3d3b547..b23d0c1 100644
--- a/scripts/boot/robot-boot.env
+++ b/scripts/boot/robot-boot.env
@@ -6,9 +6,9 @@ BLITZ_LOG_FILE="/var/log/blitz-robot/startup.log"
 
 BLITZ_5G_DIAL_DIR="/home/nvidia/5g-test/5G"
 BLITZ_5G_SERIAL_PORT="/dev/ttyUSB7"
-# 最多等 60 秒让 5G 模块对应的串口设备出现，比如 /dev/ttyUSB7
+BLITZ_5G_INTERFACE="eth0"
+BLITZ_5G_DISABLE_INTERFACES="eno3"
 BLITZ_5G_SERIAL_WAIT_SEC="60"
-# 拨号命令执行完以后，最多再等 30 秒，检查到你目标服务器 IP 的路由真的起来
 BLITZ_5G_ROUTE_WAIT_SEC="30"
 
 # Leave empty to fall back to the host part of ROBOT_SIDE_OMNISOCKET_SERVER_ADDR.
diff --git a/scripts/boot/time-sync.sh b/scripts/boot/time-sync.sh
index 396d82c..27434ce 100644
--- a/scripts/boot/time-sync.sh
+++ b/scripts/boot/time-sync.sh
@@ -10,6 +10,7 @@ CHRONY_SOURCES_DIR="/etc/chrony/sources.d"
 CHRONY_SOURCE_FILE="${CHRONY_SOURCES_DIR}/blitz-robot.sources"
 CHRONY_MAIN_CONF="/etc/chrony/chrony.conf"
 CHRONY_MAIN_CONF_BAK="/etc/chrony/chrony.conf.blitz-bak"
+CHRONY_BURST_SAMPLES="${CHRONY_BURST_SAMPLES:-1/2}"
 
 chrony_unit_name() {
   if systemctl list-unit-files chrony.service --no-legend 2>/dev/null | grep -q '^chrony\.service'; then
@@ -96,7 +97,7 @@ write_chrony_source_file
 
 CHRONY_UNIT="$(chrony_unit_name)"
 blitz_run "${STEP}" "restart-chrony" systemctl restart "${CHRONY_UNIT}"
-blitz_run "${STEP}" "burst" chronyc burst
+blitz_run "${STEP}" "burst" chronyc burst "${CHRONY_BURST_SAMPLES}"
 
 blitz_log "${STEP}" "waitsync" "start" "server=${BLITZ_TIME_SERVER_IP} port=${BLITZ_TIME_SERVER_PORT} wait_sec=${BLITZ_TIME_SYNC_WAIT_SEC} max_offset_sec=${BLITZ_TIME_SYNC_MAX_OFFSET_SEC} interval_sec=${BLITZ_TIME_SYNC_INTERVAL_SEC}" 0
 if chronyc waitsync "${BLITZ_TIME_SYNC_WAIT_SEC}" "${BLITZ_TIME_SYNC_MAX_OFFSET_SEC}" 1000 "${BLITZ_TIME_SYNC_INTERVAL_SEC}"; then