proxmox/docs/04-configuration/ADD_VLAN11_SECONDARY_IP_GUIDE.md

Add VLAN 11 Secondary IP Address - Guide

Last Updated: 2026-01-15
Status: Active Documentation Purpose: Configure machine to have both current IP and VLAN 11 IP

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Current Configuration

• Primary Interface: eth0
• Current IP: 192.168.0.4/24
• Current Gateway: 192.168.0.1
• Target VLAN 11 IP: 192.168.11.4/24
• VLAN 11 Gateway: 192.168.11.1

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Option 1: Temporary Configuration (Until Reboot)

Quick Setup:

sudo ./scripts/unifi/add-vlan11-secondary-ip.sh

Manual Commands:

# Add secondary IP
sudo ip addr add 192.168.11.4/24 dev eth0

# Add route to VLAN 11 network
sudo ip route add 192.168.11.0/24 dev eth0 src 192.168.11.4

# Verify
ip addr show eth0 | grep "inet "

Test Connectivity:

ping -c 3 192.168.11.1   # VLAN 11 gateway
ping -c 3 192.168.11.10  # ml110
ping -c 3 192.168.11.11  # r630-01
ping -c 3 192.168.11.12  # r630-02

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Option 2: Persistent Configuration (Survives Reboot)

Option 2a: Using ifupdown (if /etc/network/interfaces exists)

sudo ./scripts/unifi/add-vlan11-secondary-ip-ifupdown.sh

Manual ifupdown Configuration:

1. Edit /etc/network/interfaces:

   sudo nano /etc/network/interfaces
   

2. Add VLAN 11 alias interface:

   # VLAN 11 secondary IP address
   auto eth0:11
   iface eth0:11 inet static
       address 192.168.11.4
       netmask 255.255.255.0
       gateway 192.168.11.1
   

3. Apply configuration:

   sudo ifdown eth0:11 2>/dev/null || true
   sudo ifup eth0:11
   

Option 2b: Using Netplan (if netplan is installed)

sudo ./scripts/unifi/add-vlan11-secondary-ip-netplan.sh

Manual Netplan Configuration:

1. Find netplan config:

   ls /etc/netplan/*.yaml
   

2. Edit the config file:

   sudo nano /etc/netplan/*.yaml
   

3. Add VLAN 11 IP to eth0:

   network:
     version: 2
     renderer: networkd
     ethernets:
       eth0:
         addresses:
           - 192.168.0.4/24      # Current IP
           - 192.168.11.4/24     # VLAN 11 IP (add this)
         gateway4: 192.168.0.1   # Current gateway
         routes:
           - to: 192.168.11.0/24
             via: 192.168.11.1
         nameservers:
           addresses:
             - 192.168.0.1
             - 8.8.8.8
   

4. Apply configuration:

   sudo netplan try
   sudo netplan apply
   

5. Verify:

   ip addr show eth0 | grep "inet "
   

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Verification

After configuration, verify:

# Check IP addresses
ip addr show eth0 | grep "inet "

# Should show:
# inet 192.168.0.4/24 ... (current IP)
# inet 192.168.11.4/24 ... (VLAN 11 IP)

# Test connectivity
ping -c 3 192.168.11.1   # VLAN 11 gateway
ping -c 3 192.168.11.10  # ml110
ping -c 3 192.168.0.1    # Default gateway (should still work)

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Benefits

With both IPs configured:

1. Access to Default Network:

   • Can access UDM Pro (192.168.0.1)
   • Can access devices on 192.168.0.0/24

2. Access to VLAN 11:

   • Can access Proxmox hosts (192.168.11.10-12)
   • Can access services on VLAN 11
   • Can manage VLAN 11 resources

3. Dual Network Access:

   • Best of both worlds
   • No need to switch networks
   • Can access both simultaneously

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Troubleshooting

Issue: Cannot ping VLAN 11 gateway

Possible Causes:

1. VLAN 11 gateway not configured on UDM Pro
2. Network Isolation enabled
3. Firewall blocking

Solutions:

1. Verify UDM Pro VLAN 11 configuration
2. Check Network Isolation settings
3. Verify firewall rules

Issue: IP address not persistent after reboot

Solution: Use netplan configuration (Option 2)

Issue: Route conflicts

Solution: Check existing routes:

ip route show

Remove conflicting routes if needed:

sudo ip route del 192.168.11.0/24

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Summary

Status: ✅ Scripts ready

Quick Start:

# Temporary (until reboot)
sudo ./scripts/unifi/add-vlan11-secondary-ip.sh

# Persistent (survives reboot)
sudo ./scripts/unifi/add-vlan11-secondary-ip-netplan.sh

Result:

• ✅ Keep current IP: 192.168.0.4
• ✅ Add VLAN 11 IP: 192.168.11.4
• ✅ Access both networks simultaneously

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Last Updated: 2026-01-15