networking-controls

name: networking-controls description: Network security and connectivity standards. Use when networking controls guidance is required.

Purpose

Help agents apply networking control requirements (default deny, segmentation, controlled outbound access) in concrete recommendations and plans, without re-encoding the full guideline text.

Timeout and Backoff Configuration

Apply appropriate timeout and retry policies:

Set realistic connection timeouts
Implement exponential backoff for retries
Configure circuit breaker patterns
Apply jitter to prevent thundering herd

Timeout and retry configuration:

import time
from typing import Callable, Any

# Exponential backoff implementation
def exponential_backoff_retry(
    func: Callable,
    max_retries: int = 3,
    base_delay: float = 1.0,
    max_delay: float = 60.0,
    backoff_factor: float = 2.0
) -> Any:
    retry_count = 0
    current_delay = base_delay

    while retry_count < max_retries:
        try:
            return func()
        except Exception as e:
            retry_count += 1
            if retry_count >= max_retries:
                raise e

            # Add jitter to prevent thundering herd
            jitter = current_delay * 0.1 * (time.time() % 1)
            sleep_time = min(current_delay + jitter, max_delay)

            time.sleep(sleep_time)
            current_delay *= backoff_factor

# Circuit breaker implementation
class CircuitBreaker:
    def __init__(self, failure_threshold: int = 5, timeout: int = 60):
        self.failure_threshold = failure_threshold
        self.timeout = timeout
        self.failure_count = 0
        self.last_failure_time = None
        self.state = "CLOSED"  # CLOSED, OPEN, HALF_OPEN

    def call(self, func: Callable, *args, kwargs):
        if self.state == "OPEN":
            if time.time() - self.last_failure_time > self.timeout:
                self.state = "HALF_OPEN"
            else:
                raise Exception("Circuit breaker is OPEN")

        try:
            result = func(*args, kwargs)
            if self.state == "HALF_OPEN":
                self.state = "CLOSED"
                self.failure_count = 0
            return result
        except Exception as e:
            self.failure_count += 1
            self.last_failure_time = time.time()

            if self.failure_count >= self.failure_threshold:
                self.state = "OPEN"

            raise e

Network Performance Optimization

Load Balancing Configuration

Implement optimal load balancing strategies:

Use health checks for backend service monitoring
Apply appropriate load balancing algorithms
Implement session affinity when required
Configure geographic load balancing for global services

Load balancer configuration:

# Kubernetes service with load balancing
apiVersion: v1
kind: Service
metadata:
  name: web-service
  annotations:
    service.beta.kubernetes.io/aws-load-balancer-type: "nlb"
spec:
  selector:
    app: web-app
  ports:
  - port: 80
    targetPort: 8080
  type: LoadBalancer

# Health check configuration
apiVersion: v1
kind: Pod
metadata:
  name: web-app
spec:
  containers:
  - name: web-app
    image: nginx:latest
    ports:
    - containerPort: 8080
    livenessProbe:
      httpGet:
        path: /health
        port: 8080
      initialDelaySeconds: 30
      periodSeconds: 10
    readinessProbe:
      httpGet:
        path: /ready
        port: 8080
      initialDelaySeconds: 5
      periodSeconds: 5

Caching and CDN Integration

Implement comprehensive caching strategy:

Configure reverse proxy caching for static content
Deploy CDN for global content delivery
Apply application-level caching for dynamic content
Implement cache invalidation policies

Caching configuration:

# Nginx reverse proxy caching
proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=my_cache:10m max_size=10g
                 inactive=60m use_temp_path=off;

server {
    listen 443 ssl;
    server_name api.example.com;

    # Enable caching
    proxy_cache my_cache;
    proxy_cache_valid 200 302 10m;
    proxy_cache_valid 404 1m;

    # Cache key configuration
    proxy_cache_key "$scheme$request_method$host$request_uri";

    # Bypass cache for specific requests
    proxy_cache_bypass $http_authorization;
    proxy_no_cache $http_authorization;

    location /api/ {
        proxy_pass http://backend_servers;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
    }
}

Network Monitoring and Observability

Network Metrics Collection

Implement comprehensive network monitoring:

Monitor bandwidth utilization and throughput
Track connection counts and response times
Collect error rates and timeout statistics
Monitor security events and anomalous traffic

Monitoring configuration:

# Prometheus network monitoring rules
groups:
- name: network.rules
  rules:
  - alert: HighBandwidthUsage
    expr: rate(container_network_transmit_bytes_total[5m]) / 1024 / 1024 > 100
    for: 2m
    labels:
      severity: warning
    annotations:
      summary: "High bandwidth usage detected"
      description: "Network transmit rate is {{ $value }} MB/s"

  - alert: ConnectionPoolExhaustion
    expr: db_connections_active / db_connections_max > 0.9
    for: 1m
    labels:
      severity: critical
    annotations:
      summary: "Database connection pool nearly exhausted"
      description: "Connection pool usage is {{ $value | humanizePercentage }}"

Network Security Monitoring

Implement security event monitoring:

Monitor firewall rule hits and denials
Track unusual traffic patterns and anomalies
Collect DDoS attack indicators
Monitor authentication failures and access violations

Security monitoring setup:

#!/bin/bash
# Network security monitoring script

# Monitor failed SSH connections
monitor_ssh_failures() {
    journalctl -u sshd --since "1 hour ago" | grep "Failed password" | \
        awk '{print $1, $2, $3, $11, $13}' | \
        sort | uniq -c | sort -nr
}

# Monitor unusual traffic patterns
monitor_traffic_anomalies() {
    # Check for port scanning
    nmap -sS -p 1-65535 192.168.1.0/24 --open

    # Monitor connection spikes
    netstat -an | grep :80 | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -nr
}

# Generate security report
generate_security_report() {
    echo "=== Network Security Report ==="
    echo "Timestamp: $(date)"
    echo ""

    echo "Failed SSH attempts:"
    monitor_ssh_failures
    echo ""

    echo "Top traffic sources:"
    monitor_traffic_anomalies | head -10
    echo ""

    echo "Firewall log summary:"
    tail -n 1000 /var/log/iptables.log | grep DROP | wc -l
}

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