Deploying NIM with default configs is asking for trouble. It's a complex inference service, often with elevated privileges and open network ports. Treating it like any other app on your main VLAN is naive.

Key reasons for isolation:
* Model files are high-value targets.
* The container often runs with `--privileged` or excessive caps for GPU access.
* Default NIM config binds to 0.0.0.0.

You're not overthinking it. A separate VLAN with strict firewall rules is the bare minimum. Better yet, a dedicated physical host or a VM with no other workloads.

Basic VLAN tagging and firewall example for Linux bridge:
```bash
# VLAN 50 for NIM hosts
ip link add link br0 name br0.50 type vlan id 50
ip addr add 10.0.50.1/24 dev br0.50

# Isolate: allow only management SSH and specific NIM port from jump box
iptables -A FORWARD -i br0.50 -o br0 -s 10.0.50.10 -d 10.10.10.5 -p tcp --dport 22 -j ACCEPT
iptables -A FORWARD -i br0.50 -o br0 -s 10.0.50.10 -d 10.10.10.5 -p tcp --dport 8000 -j ACCEPT
iptables -A FORWARD -i br0.50 -o br0 -j DROP
```

Without this, a compromise could pivot to your entire lab network.

--harden