Reverse iperf3 traffic direction to DC->campus (server pushes to client)

Without -R, iperf3's client sends and the server only receives, so
traffic ran campus-host -> dc-server -- backwards for what these roles
represent: dc-serverN is the DC-hosted service, campus-hostN is the
consumer, and a real service delivers data to the consumer rather than
just absorbing uploads from it.

Refs #58

scripts/generate_traffic.sh

@@ -46,7 +46,10 @@ echo "Starting iperf3 clients for ${DURATION}s..."
 for pair in "${PAIRS[@]}"; do
     IFS=':' read -r server server_ip client <<<"$pair"
     logfile="${WORKDIR}/${client}.log"
-    docker exec "${LAB_PREFIX}-${client}" iperf3 -c "$server_ip" -p "$PORT" \
+    # -R: DC hosts the service, campus is the consumer -- data should flow
+    # server -> client (download), not client -> server, to match how a
+    # real DC-hosted service/campus-consumer pair behaves.
+    docker exec "${LAB_PREFIX}-${client}" iperf3 -c "$server_ip" -p "$PORT" -R \
         -t "$DURATION" -i 1 --forceflush -f m >"$logfile" 2>&1 &
     CLIENT_PIDS+=("$!")
 done
@@ -68,7 +71,7 @@ for ((elapsed = 0; elapsed <= DURATION; elapsed++)); do
         last_line="$(grep -E 'Mbits/sec' "$logfile" 2>/dev/null | tail -1 || true)"
         bw="$(sed -E 's/.*[[:space:]]([0-9.]+ Mbits\/sec).*/\1/' <<<"$last_line")"
         [[ -z "$last_line" ]] && bw="waiting..."
-        printf "  %-13s -> %-13s : %s\n" "$client" "$server" "$bw"
+        printf "  %-13s -> %-13s : %s\n" "$server" "$client" "$bw"
     done
     sleep 1
 done
@@ -81,5 +84,5 @@ for pair in "${PAIRS[@]}"; do
     IFS=':' read -r server _ client <<<"$pair"
     logfile="${WORKDIR}/${client}.log"
     summary="$(grep -E 'receiver' "$logfile" 2>/dev/null || true)"
-    echo "  ${client} -> ${server}: ${summary:-no data}"
+    echo "  ${server} -> ${client}: ${summary:-no data}"
 done

scripts/generate_weathermap.py

@@ -4,7 +4,7 @@ metrics, merge it into a manually-authored dashboard base, and optionally
 provision the result into Grafana.
 
 Scope (see #52): this script knows only about the weathermap panel --
-targets (node status / link tx / link rx / VXLAN tooltip queries) and
+targets (node status / link tx per side / VXLAN tooltip queries) and
 options.weathermap (nodes/links/scale/settings). It has no knowledge of the
 BGP sessions table, ports/interfaces table, or throughput panels -- those
 live in the manually-authored `configs/grafana/dashboard-base.json` and are
@@ -363,6 +363,12 @@ def build_weathermap(devices, links, interface_speeds, positions, prometheus_url
         link_defs.append({
             "id": f"{link['a_host']}-{a_gnmic_int}--{link['z_host']}-{z_gnmic_int}",
             "nodes": [{"id": link["a_host"]}, {"id": link["z_host"]}],
+            # Each side's query is that side's own tx (egress) counter, not the
+            # far end's rx -- see #57. a_host tx and z_host rx both describe the
+            # *same* A->Z flow measured from opposite ends (the a_host->z_host
+            # direction, counted twice), leaving the Z->A direction never
+            # queried by either side. Using each node's own tx gives two
+            # independent, opposite-direction measurements instead.
             "sides": {
                 "A": {
                     "bandwidth": a_bw,
@@ -371,7 +377,7 @@ def build_weathermap(devices, links, interface_speeds, positions, prometheus_url
                 },
                 "Z": {
                     "bandwidth": z_bw,
-                    "query": f"{link['z_host']} {z_gnmic_int} rx",
+                    "query": f"{link['z_host']} {z_gnmic_int} tx",
                     "labelOffset": 55, "anchor": ANCHOR["Left"], "dashboardLink": "",
                 },
             },
@@ -410,11 +416,6 @@ def build_weathermap(devices, links, interface_speeds, positions, prometheus_url
             "expr": f'rate(interfaces_interface_state_counters_out_octets{{device=~"{host_regex}", interface=~"{interface_regex}"}}[5m]) * 8',
             "legendFormat": "{{device}} {{interface}} tx",
         },
-        {
-            "refId": "C",
-            "expr": f'rate(interfaces_interface_state_counters_in_octets{{device=~"{host_regex}", interface=~"{interface_regex}"}}[5m]) * 8',
-            "legendFormat": "{{device}} {{interface}} rx",
-        },
     ]
     if vtep_hosts:
         vtep_regex = "|".join(promql_escape(h) for h in vtep_hosts)