proxmox/reports/VMID2400_CONFIGURATION_FIXES.md

VMID 2400 Configuration Fixes - Peer Connection Issues

Date: 2026-01-02
Issue: VMID 2400 was not connecting to peers (0 peers, unable to sync)
Root Cause: Two critical configuration differences compared to working VMID 2500

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Problems Identified

1. Incorrect p2p-host Configuration

VMID 2500 (Working):

p2p-host="192.168.11.250"

→ Generates enode: enode://...@192.168.11.250:30303 ✅

VMID 2400 (Broken):

p2p-host="0.0.0.0"

→ Generated enode: enode://...@0.0.0.0:30303 ❌ (invalid for peer connections)

Fix Applied:

p2p-host="192.168.11.240"

2. Missing from Permissions Allowlist

VMID 2500 (Working):

• Enode is listed in permissions-nodes.toml on all nodes
• Other nodes can accept connections from VMID 2500
• VMID 2500 can connect to other nodes

VMID 2400 (Broken):

• Enode was NOT in permissions-nodes.toml on any nodes
• Permissioning is enabled (permissions-nodes-config-file-enabled=true)
• Without being in the allowlist, VMID 2400 cannot connect to other nodes
• Other nodes will reject connections from VMID 2400

Fix Applied: Added VMID 2400's enode to permissions-nodes.toml:

"enode://38e138ea5a4b0b244e4484b5c327631b5d3c849dcb188ff3d9ff0a8b6ad7edb738303a1a948888c269aa7555e5ff47d75b7b63dbd579d05580b5442b3fa0ebfc@192.168.11.240:30303",

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Fixes Applied

1. Updated Configuration File

File: /etc/besu/config-rpc-thirdweb.toml on VMID 2400

Change:

# Before:
p2p-host="0.0.0.0"

# After:
p2p-host="192.168.11.240"

2. Updated Permissions File

File: /permissions/permissions-nodes.toml

Action: Added VMID 2400's enode to the allowlist on all nodes:

• VMIDs 1000-1004 (Validators)
• VMIDs 1500-1503 (Sentries)
• VMIDs 2500-2502 (Other RPC nodes)
• VMID 2400 (itself)

Enode Added:

"enode://38e138ea5a4b0b244e4484b5c327631b5d3c849dcb188ff3d9ff0a8b6ad7edb738303a1a948888c269aa7555e5ff47d75b7b63dbd579d05580b5442b3fa0ebfc@192.168.11.240:30303",

3. Service Restart

Restarted besu-rpc.service on VMID 2400 to apply the p2p-host change.

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Verification

Configuration Fixed ✅

• p2p-host now correctly set to 192.168.11.240
• Enode URL now shows: @192.168.11.240:30303 (instead of @0.0.0.0:30303)
• Node record shows correct IP addresses (udpAddress and tcpAddress both show 192.168.11.240:30303)

Permissions Updated ✅

• VMID 2400's enode added to permissions-nodes.toml on all 12 nodes
• Verified on VMID 2500 that the enode is present

Network Connectivity ✅

• VMID 2400 can ping VMID 2500
• VMID 2400 can connect to VMID 2500's port 30303

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Next Steps for VMIDs 2401 and 2402

When setting up VMIDs 2401 and 2402, ensure:

1. p2p-host Configuration:

   p2p-host="192.168.11.241"  # For VMID 2401
   p2p-host="192.168.11.242"  # For VMID 2402
   

2. Add Enodes to Permissions:

   • Extract the enode URL after Besu starts (check logs: journalctl -u besu-rpc | grep "Enode URL")
   • Add the enode to /permissions/permissions-nodes.toml on all nodes
   • Format: "enode://<node-id>@192.168.11.241:30303", (for VMID 2401)

3. Verify Connectivity:

   • Check that the enode shows the correct IP address (not 0.0.0.0)
   • Monitor logs for peer connections
   • Use net_peerCount RPC call to verify peer count increases

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Comparison Summary

Configuration	VMID 2500 (Working)	VMID 2400 (Before Fix)	VMID 2400 (After Fix)
p2p-host	192.168.11.250	0.0.0.0 ❌	192.168.11.240 ✅
Enode URL	@192.168.11.250:30303 ✅	@0.0.0.0:30303 ❌	@192.168.11.240:30303 ✅
In permissions-nodes.toml	Yes ✅	No ❌	Yes ✅
Peer Connections	5 peers ✅	0 peers ❌	Pending (fixes applied)

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Current Status

• ✅ Configuration file updated
• ✅ Permissions file updated on all nodes
• ✅ Service restarted with new configuration
• ✅ Enode URL now shows correct IP address
• ⏳ Waiting for peer connections to establish (may take a few minutes)

The fixes have been applied. VMID 2400 should now be able to connect to peers once Besu establishes connections with the other nodes. Monitor the logs with:

ssh root@192.168.11.10 "pct exec 2400 -- journalctl -u besu-rpc -f"

Look for messages like:

• "Connected to peer"
• "Peer count: X"
• "Importing block #X" (once synced)