explorer-monorepo/UDM_PRO_MAC_ADDRESS_VERIFICATION.md

UDM Pro MAC Address Verification

Date: 2026-01-22
Status: ⚠️ MAC ADDRESS MISMATCH DETECTED

---

UDM Pro Client List (Current)

Client 1

• MAC: bc:24:11:a8:c1:5d
• IP: 192.168.11.166
• Uptime: 3d 22h 39m 51s
• Data: 0 bps (no activity)

Client 2

• MAC: bc:24:11:18:1c:5d
• IP: 192.168.11.167
• Uptime: 3d 22h 40m 12s
• Data: 55.5 MB (active)

Client 3

• MAC: bc:24:11:8d:ec:b7
• IP: 192.168.11.168
• Uptime: Jan 22 2026 1:36 PM
• Data: 0 bps (no activity)

---

Expected MAC Addresses (From Container Config)

From Proxmox Configuration

• 192.168.11.166 (eth0, net0): MAC BC:24:11:18:1C:5D
• 192.168.11.167 (eth1, net1): MAC BC:24:11:A8:C1:5D

Expected Mapping

• 192.168.11.166 → MAC bc:24:11:18:1c:5d ✅
• 192.168.11.167 → MAC bc:24:11:a8:c1:5d ✅

---

UDM Pro Mapping (Actual)

• 192.168.11.166 → MAC bc:24:11:a8:c1:5d ❌ WRONG
• 192.168.11.167 → MAC bc:24:11:18:1c:5d ❌ WRONG

---

Analysis

Issue

UDM Pro has swapped MAC addresses:

• It shows MAC bc:24:11:a8:c1:5d for IP 192.168.11.166 (should be .167)
• It shows MAC bc:24:11:18:1c:5d for IP 192.168.11.167 (should be .166)

Possible Causes

1. ARP confusion: ARP table may have incorrect mappings
2. Traffic source: Traffic from 192.168.11.166 may have used wrong source MAC
3. UDM Pro caching: UDM Pro may have cached old MAC-to-IP mappings
4. Network routing: Kernel may be using wrong interface for routing

---

Verification

Checking actual MAC addresses from container...

---

Resolution

Option 1: Clear ARP Cache

Clear ARP cache on UDM Pro and network devices to force re-discovery:

• UDM Pro may need to refresh its ARP table
• Wait for ARP entries to expire and renew

Option 2: Generate Correct Traffic

Force traffic from correct IP-MAC pairs:

• Generate traffic from 192.168.11.166 using eth0 (correct MAC)
• Generate traffic from 192.168.11.167 using eth1 (correct MAC)

Option 3: Wait for Natural Refresh

ARP entries expire naturally (usually 4 hours)

• UDM Pro will eventually update with correct mappings
• Traffic will naturally correct the mappings over time

---

Status: MAC addresses swapped in UDM Pro - verifying actual mappings...