Phase 1C: TB4 System Integration

This section covers the final system integration steps for Thunderbolt 4, including initramfs updates and system configuration.

Step 7: Update Initramfs and Reboot

Apply all TB4 configuration changes:

# Update initramfs on all nodes:
for node in n2 n3 n4; do
  ssh $node "update-initramfs -u -k all"
done

# Reboot all nodes to apply changes:
echo "Rebooting all nodes - wait for them to come back online..."
for node in n2 n3 n4; do
  ssh $node "reboot"
done

# Wait and verify after reboot:
echo "Waiting 60 seconds for nodes to reboot..."
sleep 60

# Verify TB4 interfaces after reboot:
for node in n2 n3 n4; do
  echo "=== TB4 interfaces on $node after reboot ==="
  ssh $node "ip link show | grep -E '(en05|en06)'"
  ssh $node "ip addr show en05 | grep 'inet '"
  ssh $node "ip addr show en06 | grep 'inet '"
done

Expected result: TB4 interfaces should be named en05 and en06 with proper MTU settings and static IP addresses assigned.

Step 8: Enable IPv4 Forwarding

Essential: TB4 mesh requires IPv4 forwarding for OpenFabric routing.

# Configure IPv4 forwarding on all nodes:
for node in n2 n3 n4; do
  ssh $node "echo 'net.ipv4.ip_forward=1' >> /etc/sysctl.conf"
  ssh $node "sysctl -p"
done

Verify forwarding enabled:

for node in n2 n3 n4; do
  echo "=== IPv4 forwarding on $node ==="
  ssh $node "sysctl net.ipv4.ip_forward"
done

Expected output: net.ipv4.ip_forward = 1 on all nodes.

TB4 Physical Topology

The 3-node mesh uses a triangle topology with the following connections:

n2 en06 (10.100.0.5/30)  ←→  n3 en05 (10.100.0.6/30)   [subnet: 10.100.0.4/30]
n3 en06 (10.100.0.9/30)  ←→  n4 en05 (10.100.0.10/30)  [subnet: 10.100.0.8/30]
n4 en06 (10.100.0.14/30) ←→  n2 en05 (10.100.0.2/30)   [cross-subnet link]

This creates a redundant triangle mesh where each node has two paths to every other node.

Next Steps

After completing TB4 system integration, proceed to SDN OpenFabric Configuration to set up the Proxmox SDN fabric for mesh routing.