Skip to main content

Floating IPs

Floating IPs provide static, reassignable IP addresses that can be moved between VPS instances for high availability and failover scenarios.

Overview​

Floating IPs offer:

  • Static IP Addresses: Never change, even when reassigned
  • High Availability: Quick failover between instances
  • Load Balancing: Distribute traffic across multiple servers
  • Disaster Recovery: Instant IP reassignment during outages

Creating Floating IPs​

Via Dashboard​

  1. Navigate to Networking > Floating IPs
  2. Click Reserve Floating IP
  3. Select region and assign to instance
  4. Configure reverse DNS (optional)

Via CLI​

# Reserve a floating IP
lineserve network reserve-floating-ip \
  --region us-east-1 \
  --name "web-server-ip"

# Assign to instance
lineserve network assign-floating-ip \
  --ip 203.0.113.10 \
  --instance-id vps-12345678

# List floating IPs
lineserve network list-floating-ips

Configuration​

Assign Floating IP​

# Assign to VPS instance
lineserve network assign-floating-ip \
  --ip 203.0.113.10 \
  --instance-id vps-12345678

# Unassign floating IP
lineserve network unassign-floating-ip \
  --ip 203.0.113.10

Network Interface Setup​

# Configure on Ubuntu/Debian
cat >> /etc/netplan/01-netcfg.yaml << EOF
network:
  version: 2
  ethernets:
    eth0:
      addresses:
        - 203.0.113.10/32
      routes:
        - to: 0.0.0.0/0
          via: 10.0.0.1
          metric: 100
EOF

netplan apply

High Availability Setup​

Automatic Failover Script​

#!/bin/bash
# failover.sh - Automatic floating IP failover

PRIMARY_INSTANCE="vps-12345678"
BACKUP_INSTANCE="vps-87654321"
FLOATING_IP="203.0.113.10"

# Check primary server health
if ! ping -c 3 $PRIMARY_INSTANCE > /dev/null; then
    echo "Primary server down, failing over..."
    
    # Reassign floating IP to backup
    lineserve network assign-floating-ip \
      --ip $FLOATING_IP \
      --instance-id $BACKUP_INSTANCE
    
    echo "Failover completed"
fi

Load Balancer Integration​

# Configure HAProxy with floating IP
cat > /etc/haproxy/haproxy.cfg << EOF
global
    daemon

defaults
    mode http
    timeout connect 5000ms
    timeout client 50000ms
    timeout server 50000ms

frontend web_frontend
    bind 203.0.113.10:80
    default_backend web_servers

backend web_servers
    balance roundrobin
    server web1 10.0.1.10:80 check
    server web2 10.0.1.11:80 check
EOF

Use Cases​

Web Server Failover​

  • Primary web server with floating IP
  • Backup server ready for instant takeover
  • DNS points to floating IP for zero downtime

Database Clustering​

  • Master database with floating IP
  • Slave promotion with IP reassignment
  • Application connections remain stable

API Gateway​

  • Multiple API servers behind floating IP
  • Load balancing and health checks
  • Seamless server maintenance

Pricing​

RegionPrice per IP/month
US East$3.00
US West$3.00
Europe$3.50
Asia Pacific$4.00

Additional Costs:

  • Bandwidth: Standard rates apply
  • No charge for IP reassignment

Best Practices​

Security​

  • Configure firewall rules for floating IPs
  • Use security groups for access control
  • Monitor traffic and access logs

Monitoring​

# Monitor floating IP status
lineserve network get-floating-ip --ip 203.0.113.10

# Set up health checks
lineserve monitoring create-check \
  --type http \
  --url http://203.0.113.10/health \
  --interval 30s

Automation​

# Python script for automated failover
import requests
import time

def check_server_health(ip):
    try:
        response = requests.get(f"http://{ip}/health", timeout=5)
        return response.status_code == 200
    except:
        return False

def failover_floating_ip(floating_ip, backup_instance):
    # Lineserve API call to reassign IP
    pass

# Health check loop
while True:
    if not check_server_health("203.0.113.10"):
        failover_floating_ip("203.0.113.10", "vps-backup")
    time.sleep(30)

Troubleshooting​

Common Issues​

IP Not Responding

  • Check instance network configuration
  • Verify floating IP assignment
  • Review firewall rules

Slow Failover

  • Optimize health check intervals
  • Use API for faster reassignment
  • Pre-configure backup instances

Network Conflicts

  • Ensure unique IP assignments
  • Check routing table conflicts
  • Verify subnet configurations

API Reference​

Reserve Floating IP​

POST /v1/network/floating-ips
{
  "region": "us-east-1",
  "name": "web-server-ip"
}

Assign Floating IP​

PUT /v1/network/floating-ips/{ip}/assign
{
  "instance_id": "vps-12345678"
}

List Floating IPs​

GET /v1/network/floating-ips

Next Steps​