Networking Metrics Reference

Common Troubleshooting Metrics

• RTT (Latency): networking.googleapis.com/cloud_netslo/active_probing/rtt
• Packet Loss: networking.googleapis.com/cloud_netslo/active_probing/probe_count
• VM Throughput: compute.googleapis.com/instance/network/received_bytes_count
• VM Sent Packets: compute.googleapis.com/instance/network/sent_packets_count
• VM Received Packets: compute.googleapis.com/instance/network/received_packets_count
• NAT Port Exhaustion: compute.googleapis.com/nat/dropped_sent_packets_count
• NAT Sent Packets: compute.googleapis.com/nat/sent_packets_count
• VPN Dropped Received Packets: vpn.googleapis.com/network/dropped_received_packets_count
• VPN Dropped Sent Packets: vpn.googleapis.com/network/dropped_sent_packets_count
• Internal Latency (RTT): networking.googleapis.com/vm_flow/rtt. Measures internal VM-to-VM traffic within Google Cloud.
• External Latency (RTT): networking.googleapis.com/vm_flow/external_rtt. Measures traffic to and from the internet.

Distribution Parsing Standard

When querying metrics of type DISTRIBUTION (like RTT), align the data with ALIGN_PERCENTILE_50 to ensure the output can be parsed as a simple numeric value.

Dynamic Discovery

• Primary (Cloud Monitoring MCP): Use list_metric_descriptors with a filter.

  • Prefix: Filter by prefix, using starts_with(). Common prefixes:
    • metric.type = starts_with("networking.googleapis.com/")
    • metric.type = starts_with("router.googleapis.com/")
    • metric.type = starts_with("vpn.googleapis.com/")
    • metric.type = starts_with("compute.googleapis.com/")
  • Substring: metric.type = has_substring("network") OR metric.type = has_substring("packet") OR metric.type = has_substring("nat")

• Fallback (CLI/CURL): If MCP tools not available, use gcloud or curl.

  curl -s -H "Authorization: Bearer $(gcloud auth print-access-token)"
  "https://monitoring.googleapis.com/v3/projects/{project_id}/metricDescriptors?filter=metric.type=starts_with(%22{prefix}%22)"
  | jq -r '.metricDescriptors[] | "\(.type): \(.description)"'
  
  curl -s -H "Authorization: Bearer $(gcloud auth print-access-token)" \
  "https://monitoring.googleapis.com/v3/projects/{project_id}/timeSeries?" \
  "filter=metric.type%3D%22{metric_name}%22&" \
  "interval.startTime={start_time}&" \
  "interval.endTime={end_time}&" \
  "aggregation.alignmentPeriod=3600s&" \
  "aggregation.perSeriesAligner=ALIGN_PERCENTILE_50" \
  | jq '.timeSeries[] | {metric: .metric.type, points: .points[:5]}'
  

• Detailed Schema: ALWAYS query the full descriptor for a specific metric before use to identify available labels. Metric types like vm_flow/rtt often use resource.labels.zone for the local zone and metric.labels.remote_zone for the peer.