DNS setup

​

Overview

​

DNS Requirements

​

1. A Domain Name

• Purchase from any domain registrar (Namecheap, GoDaddy, Cloudflare, etc.)
• Use a subdomain of an existing domain you own
• Register a free subdomain from services like FreeDNS or Duck DNS

​

2. DNS Management Access

• Your domain registrar’s control panel
• A dedicated DNS provider (Cloudflare, Route53, etc.)
• Your server’s DNS management interface

​

3. Your Server’s Public IP

# On your server, run:
curl -4 ifconfig.me
# or
wget -qO- ifconfig.me

​

DNS Record Configuration

​

Basic Setup (A Record)

​

Recommended Configuration

​

1. A Record (Required)

Type: A
Name: s (or your subdomain)
Value: YOUR_SERVER_IP
TTL: 3600

​

2. AAAA Record (Optional, for IPv6)

Type: AAAA
Name: s (or your subdomain)
Value: YOUR_SERVER_IPv6
TTL: 3600

​

3. CAA Record (Optional, for TLS certificates)

Type: CAA
Name: s (or your subdomain)
Value: 0 issue "letsencrypt.org"
TTL: 3600

​

Provider-Specific Instructions

​

DNS Propagation

​

What is DNS Propagation?

1. Your DNS provider updates its authoritative nameservers (instant)
2. Recursive DNS servers worldwide cache the old record (based on TTL)
3. Cached records expire and servers fetch the new record (can take hours)
4. All servers eventually have the new record (complete propagation)

​

Propagation Timeline

• Immediate: Your DNS provider’s servers (1-5 minutes)
• Fast: Major DNS resolvers like Google (8.8.8.8) and Cloudflare (1.1.1.1) (5-30 minutes)
• Average: Most ISP DNS servers (1-4 hours)
• Slow: Some regional or caching servers (up to 24-48 hours)

​

Monitoring Propagation

​

Command Line Tools

# Check using different DNS servers
dig @8.8.8.8 s.example.com +short
dig @1.1.1.1 s.example.com +short
dig @208.67.222.222 s.example.com +short

# Or using nslookup
nslookup s.example.com 8.8.8.8
nslookup s.example.com 1.1.1.1

​

Online Tools

• whatsmydns.net - Check DNS propagation globally
• dnschecker.org - Multi-location DNS checker
• mxtoolbox.com - Comprehensive DNS tools

​

Testing DNS Configuration

​

Before Connecting

​

1. Verify A Record Resolution

# Should return your server's IP address
dig +short s.example.com

# Or using nslookup
nslookup s.example.com

123.45.67.89

​

2. Test from Different DNS Resolvers

# Google DNS
dig @8.8.8.8 s.example.com +short

# Cloudflare DNS
dig @1.1.1.1 s.example.com +short

# OpenDNS
dig @208.67.222.222 s.example.com +short

​

3. Verify Reverse DNS (Optional)

# Replace with your server's IP
dig -x 123.45.67.89 +short

​

After Server Deployment

​

4. Test Server Connectivity

# Test HTTP connectivity
curl -I http://s.example.com

# Test HTTPS connectivity (if TLS is configured)
curl -I https://s.example.com

​

5. Verify DNS Resolution from Your Server

# Check if the server can resolve its own domain
dig +short s.example.com

# Should return the server's public IP
curl -4 ifconfig.me

​

Using Custom DNS Resolver

​

Why Use a Custom DNS Resolver?

1. Bypass DNS censorship: Some ISPs or countries block certain domains
2. Improve reliability: Your ISP’s DNS might be slow or unreliable
3. Direct resolution: Use your server’s DNS for better privacy
4. Troubleshooting: Test different resolvers to find the most reliable

​

Recommended DNS Resolvers

​

Setting DNS Resolver in SlipStream GUI

1. Open SlipStream GUI
2. In the DNS Resolver field, enter your chosen resolver (e.g., 8.8.8.8:53)
3. Click “DNS Checker” to test different resolvers
4. Click “Use” on any OK result to apply it automatically
5. Click “Start VPN” to connect

​

Using Your Server as DNS Resolver

DNS Resolver: YOUR_SERVER_IP:53
Domain: s.example.com

• All DNS queries go through your server
• Your ISP can’t see which domains you’re resolving
• DNS responses aren’t cached by third-party resolvers

​

Troubleshooting DNS Issues

​

Issue: Domain Doesn’t Resolve

• dig or nslookup returns no results
• SlipStream GUI can’t connect to server

1. Check DNS record configuration
   # Verify record exists
   dig s.example.com +trace
   
2. Wait for propagation
   • Changes can take up to 24 hours
   • Use online propagation checkers
3. Verify nameservers
   # Check your domain's nameservers
   dig NS example.com +short
   
4. Clear local DNS cache
   # macOS
   sudo dscacheutil -flushcache
   sudo killall -HUP mDNSResponder
   
   # Windows (Command Prompt as Admin)
   ipconfig /flushdns
   
   # Linux
   sudo systemd-resolve --flush-caches
   

​

Issue: Slow DNS Resolution

• Connections take a long time to establish
• Intermittent timeouts

1. Use a faster DNS resolver
   • Try 1.1.1.1:53 (Cloudflare) or 8.8.8.8:53 (Google)
2. Test resolver performance
   # Time DNS query
   time dig @8.8.8.8 s.example.com +short
   time dig @1.1.1.1 s.example.com +short
   
3. Use SlipStream GUI DNS Checker
   • Built-in tool to test multiple resolvers
   • Shows response time for each
   • Click “Use” on the fastest resolver

​

Issue: DNS Works but Connection Fails

• dig resolves correctly
• SlipStream GUI still can’t connect

1. Verify server is running
   # On your server
   sudo systemctl status slipstream-server
   
2. Check firewall rules
   # Ensure ports are open
   sudo ufw status
   sudo firewall-cmd --list-all
   
3. Test port connectivity
   # Test if server is reachable
   telnet s.example.com 443
   # or
   nc -zv s.example.com 443
   
4. Verify TLS certificates
   # Check certificate validity
   openssl s_client -connect s.example.com:443
   

​

Issue: Cloudflare Proxy Enabled

• DNS resolves to Cloudflare IP instead of your server
• Connection fails with timeout or proxy errors

1. Disable Cloudflare proxy
   • Go to Cloudflare DNS settings
   • Click the orange cloud icon next to your record
   • Change to gray cloud (DNS only)
   • Wait for propagation
2. Verify proxy status
   # Should return YOUR server IP, not Cloudflare IP
   dig s.example.com +short
   

​

Issue: Wrong IP Address Returned

• DNS resolves to wrong IP address
• Old IP address still cached

1. Verify current configuration
   • Check your DNS provider’s control panel
   • Ensure A record points to correct IP
2. Check TTL and wait
   • Old record may still be cached
   • Wait for TTL to expire (check propagation)
3. Use direct nameserver query
   # Query authoritative nameserver directly
   dig @ns1.your-provider.com s.example.com +short
   
4. Clear caches everywhere
   • Local DNS cache (see above)
   • Browser DNS cache (restart browser)
   • Router DNS cache (restart router)

​

Issue: DNS Works Intermittently

• Sometimes resolves, sometimes fails
• Connection drops randomly

1. Check for multiple A records
   # Should return single IP
   dig s.example.com +short
   
   Remove duplicate or incorrect records.
2. Test DNS stability
   # Query multiple times
   for i in {1..10}; do dig @8.8.8.8 s.example.com +short; done
   
   All results should be identical.
3. Use more reliable DNS resolver
   • Switch to 8.8.8.8:53 or 1.1.1.1:53
   • Test with DNS Checker tool
4. Check server uptime
   # On your server
   uptime
   sudo systemctl status slipstream-server
   

​

Advanced DNS Configuration

​

Multiple Servers (Load Balancing)

Type: A
Name: s
Value: SERVER_IP_1
TTL: 300

Type: A
Name: s
Value: SERVER_IP_2
TTL: 300

​

Geo-Based Routing

• North America: Server in USA
• Europe: Server in Germany
• Asia: Server in Singapore

​

Split Horizon DNS

• Internal network: Resolves to internal IP
• External network: Resolves to public IP

​

Next Steps