# Cloudflare DNS Duplicate Records - Fix Guide

## ⚠️ Current Issues

### Duplicate A Records Found:

1. **besu.d-bis.org** - 2 A records:
   - `20.215.32.42` (cf-proxied:true)
   - `70.153.83.83` (cf-proxied:true)

2. **blockscout.d-bis.org** - 2 A records:
   - `20.215.32.42` (cf-proxied:true)
   - `70.153.83.83` (cf-proxied:true)

3. **explorer.d-bis.org** - 2 A records:
   - `20.215.32.42` (cf-proxied:true)
   - `70.153.83.83` (cf-proxied:true)

4. **d-bis.org** (root) - 2 A records:
   - `20.215.32.42` (cf-proxied:true)
   - `20.215.32.15` (cf-proxied:true)

## 🔍 Problems Caused

- **Random IP Selection**: DNS round-robin causes connections to alternate between IPs
- **HTTP 522 Errors**: When Cloudflare proxies to a down or misconfigured IP
- **Connection Failures**: If one IP doesn't have the correct service
- **Unpredictable Behavior**: Load balancing without proper health checks

## ✅ Recommended Fixes

### Step 1: Remove Duplicate Records

Remove one of each duplicate A record. Keep the IP that:
- Has the correct service running
- Is the primary/reliable endpoint
- Matches current deployment

### Step 2: Service-Specific Recommendations

#### **explorer.d-bis.org** → Blockscout
- **Keep**: Single IP that has Blockscout running (port 4000)
- **Remove**: Duplicate IP
- **Note**: Should point to the node running Blockscout (currently eus2: 10.4.1.4)

#### **besu.d-bis.org** → Besu RPC
- **Keep**: Single IP that has Besu RPC enabled (port 8545)
- **Remove**: Duplicate IP
- **Note**: Should point to a reliable RPC node

#### **blockscout.d-bis.org** → Blockscout (alternative)
- **Keep**: Same IP as explorer.d-bis.org OR remove if not needed
- **Remove**: Duplicate or redundant record

#### **d-bis.org** (root)
- **Keep**: Primary IP (20.215.32.15 based on comment)
- **Remove**: 20.215.32.42 (seems to be duplicate)

### Step 3: Verify IPs Match Deployment

Before making changes, verify:
1. Which IPs are actually in use
2. Which services are running on each IP
3. Which IP is the Nginx proxy/gateway

### Step 4: Cloudflare Proxy Settings

- **explorer.d-bis.org**: Keep `cf-proxied:true` (HTTPS through Cloudflare)
- **besu.d-bis.org**: Consider `cf-proxied:false` if direct RPC access needed
- **blockscout.d-bis.org**: Match explorer.d-bis.org settings

## 📝 DNS Record Template (Recommended)

```
# Primary explorer endpoint
explorer.d-bis.org.  1  IN  A  20.215.32.42  ; cf-proxied:true

# Besu RPC endpoint (if needed publicly)
besu.d-bis.org.  1  IN  A  20.215.32.42  ; cf-proxied:false or true

# Root domain
d-bis.org.  1  IN  A  20.215.32.15  ; cf-proxied:true

# Remove duplicates:
# - Remove second IP from besu.d-bis.org
# - Remove second IP from blockscout.d-bis.org
# - Remove second IP from explorer.d-bis.org
# - Remove 20.215.32.42 from d-bis.org root
```

## 🔧 Verification Steps

After making changes:

1. **Wait for DNS propagation** (usually 1-5 minutes)
2. **Test DNS resolution**:
   ```bash
   dig explorer.d-bis.org
   dig besu.d-bis.org
   ```
3. **Test HTTP endpoints**:
   ```bash
   curl -I https://explorer.d-bis.org
   curl -X POST http://besu.d-bis.org:8545 -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","method":"eth_chainId","params":[],"id":1}'
   ```
4. **Check for HTTP 522 errors** (should be resolved)

## ⚠️ Important Notes

- **Don't remove records immediately** - First verify which IP is correct
- **Keep backup** of current DNS settings
- **Test changes** in a staging environment if possible
- **Monitor** after changes for any service disruption

## 🚨 Current Deployment Context

- **Nginx Proxy**: 20.160.58.99 (private network gateway)
- **Besu Nodes**: 10.1.1.4 - 10.5.1.4 (private IPs)
- **Blockscout**: Deployed on eus2 node (10.4.1.4)

Need to map public IPs (20.215.32.42, 70.153.83.83, etc.) to actual services before removing duplicates.