Netcup VPS Provider

Netcup is a German hosting provider offering VPS and DNS services. This skill covers DNS API automation and VPS management for ARM G11 servers.

Quick Reference

DNS API Workflow

1. Login       → Get session ID
2. Query       → infoDnsZone, infoDnsRecords
3. Update      → updateDnsRecords (replaces ALL records)
4. Logout      → End session

Authentication

const response = await fetch(NETCUP_API, {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    action: 'login',
    param: {
      customernumber: '12345',
      apikey: 'abc123...',
      apipassword: 'xyz789...'
    }
  })
});
// Returns: { responsedata: { apisessionid: 'session-id' } }

Get Records

{
  action: 'infoDnsRecords',
  param: {
    customernumber: '12345',
    apikey: 'abc123...',
    apisessionid: 'session-id',
    domainname: 'example.com'
  }
}

Update Records

IMPORTANT: This replaces ALL records in the zone. Always send the complete record set.

{
  action: 'updateDnsRecords',
  param: {
    customernumber: '12345',
    apikey: 'abc123...',
    apisessionid: 'session-id',
    domainname: 'example.com',
    dnsrecordset: {
      dnsrecords: [
        { hostname: '@', type: 'A', destination: '203.0.113.50' },
        { hostname: 'mail', type: 'A', destination: '203.0.113.50' },
        { hostname: '@', type: 'MX', priority: '10', destination: 'mail.example.com' },
        { hostname: '@', type: 'TXT', destination: 'v=spf1 mx ~all' }
      ]
    }
  }
}

API Limitations

Email DNS Records

Standard records for Mox email server:

External Domains

For domains registered elsewhere (Netim, Gandi, etc.):

1. Add zone in Netcup CCP: Products → Domain → DNS → Add DNS Zone
2. At registrar: Change nameservers to:

- root-dns.netcup.net - second-dns.netcup.net - third-dns.netcup.net

1. Wait: 24-48 hours for NS propagation
2. Manage via API: Works like Netcup-registered domains

VPS Management

Reverse DNS (PTR)

Set in Server Control Panel → Network → IPv4/IPv6 address → Edit PTR

Critical for email: PTR must match mail server hostname (e.g., mail.example.com)

Firewall (Port 25)

New VPS may have port 25 blocked:

1. SCP → Firewall
2. Remove "netcup Mail block" policy
3. Save changes

Reference Files

Common Issues

Verification Commands

# Check A record
dig A mail.example.com @8.8.8.8 +short

# Check MX
dig MX example.com @8.8.8.8 +short

# Check SPF
dig TXT example.com @8.8.8.8 +short | grep spf

# Check DKIM
dig TXT selector._domainkey.example.com @8.8.8.8 +short

# Check DMARC
dig TXT _dmarc.example.com @8.8.8.8 +short

# Check PTR (reverse DNS)
dig -x YOUR_IP +short

# Check from multiple locations
# Use: https://dnschecker.org/

Official Documentation

• Netcup Help Center
• DNS API Wiki
• Firewall Documentation