Network setup & IP aliases

A full 50k install presents 20 IPs × 2,500 ports. Those IPs are ordinary aliases on a single interface — no extra NICs required. rcfg-sim ships an idempotent helper to manage them.

The address plan

The defaults assume a contiguous IP range starting at 10.50.0.1, each IP serving ports 10000–12499 (2,500 ports). The generator’s --ip-base, --ip-count, --devices-per-ip, and --port-start flags define this plan, and it is written into the manifest so the server knows exactly what to bind.

single host
├── 10.50.0.1   ports 10000-12499 → 2,500 devices
├── 10.50.0.2   ports 10000-12499 → 2,500 devices
└── … 10.50.0.20 ports 10000-12499 → 2,500 devices
                                      ───────────────
                                      50,000 devices total

Creating the aliases

Use the Makefile wrappers around deploy/ip-aliases.sh:

sudo make deploy-aliases      # add the configured IP aliases
sudo make remove-aliases      # remove them again

The script is idempotent — re-running it will not create duplicates — and works against either the loopback interface (for a self-contained rig) or a routable interface (when an external NCM platform must reach the simulated fleet).

Loopback vs routable

• Loopback aliases keep everything on one host: the simulator and the tool under test run side by side. Great for CI and single-box benchmarking.
• Routable aliases expose the fleet to other hosts on the network, so a separate collector or NCM server can connect across the wire — closer to a real deployment.

Verifying

ip -brief addr show          # confirm the aliases are present
ss -tlnp | grep rcfg-sim     # confirm listeners are bound (once running)

Next

With aliases in place and configs generated, start the instances — see System install and Running the server.