Private Networks

Private networks allow secure, isolated communication between your DanubeData resources without exposing traffic to the public internet. This guide covers setup, configuration, and best practices for private networking.

Overview

Private networks provide:

Isolated Communication: Traffic never leaves the datacenter
High Performance: 10 Gbps+ bandwidth, sub-millisecond latency
Zero Cost: No charges for private network traffic
Enhanced Security: No exposure to internet threats
VLAN Isolation: Network-level isolation between tenants

Use Cases

Database Connectivity

Connect application servers to databases securely:

VPS (Public) ← Users
    ↓ (Private Network)
Database (Private only)

Benefits:

Database not exposed to internet
Free bandwidth for database queries
Lower latency
Enhanced security

Multi-Tier Applications

Separate tiers on private network:

Load Balancer (Public)
    ↓ (Private Network)
Web Servers (Public + Private)
    ↓ (Private Network)
App Servers (Private only)
    ↓ (Private Network)
Database (Private only)

Microservices

Connect microservices internally:

Service-to-service communication on private network
API gateway on public network
Internal services on private network only
Reduced latency and cost

Creating Private Networks

Via Dashboard

Navigate to Networking > Private Networks
Click Create Private Network
Configure:
- Name: Descriptive name (e.g., "production-internal")
- Region: Select datacenter
- Description: Optional description
Click Create

Network will be ready immediately.

Network Details

Each private network includes:

Network ID: Unique identifier
CIDR Block: Private IP range (e.g., 10.0.1.0/24)
Gateway: Network gateway address
DNS: Private DNS resolution

Attaching Resources

Attach VPS Instance

Go to VPS instance
Click Networking tab
Click Attach to Private Network
Select private network
Click Attach

Instance will receive private IP within 10-45 seconds.

Attach Database

Go to Database instance
Click Networking tab
Click Enable Private Network
Select private network
Click Enable

Database will get private endpoint.

Attach Cache

Same process as database:

Navigate to Cache instance
Enable private networking
Select network
Use private endpoint for connections

Connecting via Private Network

Using Private IP Addresses

Each resource gets a private IP:

VPS-1: 10.0.1.10
VPS-2: 10.0.1.11
Database: 10.0.1.20
Cache: 10.0.1.30

Application Configuration

Web Application to Database

# Use private IP for database connection
DATABASE_HOST = '10.0.1.20'  # Private IP
DATABASE_PORT = 5432
DATABASE_NAME = 'myapp'

# Instead of public host
# DATABASE_HOST = 'db-postgres-123456.danubedata.com'

Laravel Configuration

// .env
DB_HOST=10.0.1.20  # Private IP instead of public hostname
DB_PORT=5432
DB_DATABASE=myapp
DB_USERNAME=dbuser
DB_PASSWORD=password

Node.js Configuration

const config = {
  database: {
    host: '10.0.1.20', // Private IP
    port: 5432,
    database: 'myapp'
  },
  redis: {
    host: '10.0.1.30', // Private IP
    port: 6379
  }
};

Private DNS

Automatic DNS Resolution

Resources on private network can be resolved by name:

# Instead of using IP
ping 10.0.1.20

# Use hostname
ping db-postgres-123456.internal

Private DNS automatically configured for all attached resources.

Private Hostnames

Format: {resource-name}.internal

Examples:

web-server-1.internal
db-postgres-123456.internal
redis-cache-123456.internal

Network Configuration

Checking Private Network

On Linux VPS:

# List network interfaces
ip addr show

# Should see private interface (e.g., eth1)
# 3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP>
#     inet 10.0.1.10/24 brd 10.0.1.255 scope global eth1

# Test connectivity
ping 10.0.1.20

# Check routing
ip route show

Firewall Configuration

Private network traffic bypasses firewalls by default, but you can still control access:

Navigate to Networking > Firewalls
Create rules for private network CIDR
Apply to specific resources

Example: Allow only database port from private network:

Source: 10.0.1.0/24
Protocol: TCP
Port: 5432
Action: Allow

Multiple Private Networks

You can create multiple isolated networks:

Use Cases

Environment Separation:

- production-network (10.0.1.0/24)
- staging-network (10.0.2.0/24)
- development-network (10.0.3.0/24)

Application Separation:

- app1-network (10.0.10.0/24)
- app2-network (10.0.20.0/24)

Tier Separation:

- web-tier (10.0.1.0/24)
- app-tier (10.0.2.0/24)
- data-tier (10.0.3.0/24)

Connecting Networks

Resources cannot communicate across different private networks by default. To enable:

Use a gateway VPS attached to both networks
Configure routing/NAT on gateway
Or use public network for cross-network communication

Performance

Throughput

Up to 10 Gbps: Internal network bandwidth
No Throttling: Consistent performance
Zero Cost: Unlimited free traffic

Latency

< 1ms: Within same datacenter
Consistent: No internet routing delays

Benchmarking

Test private network performance:

# Install iperf3
apt-get install iperf3

# On server (10.0.1.10)
iperf3 -s

# On client (10.0.1.11)
iperf3 -c 10.0.1.10

# Expected results:
# [ ID] Interval           Transfer     Bitrate
# [  5]   0.00-10.00  sec  11.2 GBytes  9.62 Gbits/sec

Security Best Practices

Isolate Sensitive Resources

Keep databases on private network only
Don't expose internal services publicly
Use jump boxes for administrative access
Segment by environment or application

Principle of Least Privilege

Only attach necessary resources to each network
Use multiple networks for isolation
Firewall rules for additional control
Regular security audits

Monitoring

Monitor private network traffic
Alert on unusual patterns
Log access to sensitive resources
Regular vulnerability scanning

Troubleshooting

Cannot Reach Private IP

Check attachment:

# Verify private IP assigned
ip addr show eth1

# If no private IP, check dashboard
# Resource should show "Connected" to private network

Check routing:

# Verify route exists
ip route | grep 10.0.1.0

# Should see:
# 10.0.1.0/24 dev eth1 proto kernel scope link src 10.0.1.10

Test connectivity:

# Ping other resource
ping 10.0.1.20

# If fails, check:
# - Both resources attached to same network
# - Both resources in same datacenter
# - No firewall rules blocking

Slow Performance on Private Network

Check network interface:

# Verify link is up and speed
ethtool eth1

# Should show:
# Speed: 10000Mb/s
# Duplex: Full
# Link detected: yes

Monitor bandwidth:

# Install iftop
apt-get install iftop

# Monitor traffic
iftop -i eth1

Private DNS Not Resolving

Check DNS configuration:

# View DNS config
cat /etc/resolv.conf

# Should include DanubeData DNS
# nameserver 10.0.0.1

Test resolution:

# Test private hostname
nslookup db-postgres-123456.internal

# If fails, use IP address directly
# Contact support if DNS needed

Private Networks

Overview

Use Cases

Database Connectivity

Multi-Tier Applications

Microservices

Creating Private Networks

Via Dashboard

Network Details

Attaching Resources

Attach VPS Instance

Attach Database

Attach Cache

Connecting via Private Network

Using Private IP Addresses

Application Configuration

Web Application to Database

Laravel Configuration

Node.js Configuration

Private DNS

Automatic DNS Resolution

Private Hostnames

Network Configuration

Checking Private Network

Firewall Configuration

Multiple Private Networks

Use Cases

Connecting Networks

Performance

Throughput

Latency

Benchmarking

Security Best Practices

Isolate Sensitive Resources

Principle of Least Privilege

Monitoring

Troubleshooting

Cannot Reach Private IP

Slow Performance on Private Network

Private DNS Not Resolving

Related Documentation