routeros-mndp

# MNDP — MikroTik Neighbor Discovery Protocol MNDP is the UDP broadcast/multicast protocol that RouterOS uses for automatic device discovery on the local network. It is the same protocol WinBox uses to find routers. Every RouterOS device participates by default. ## Why This Matters for Agents - **`/ip/neighbor`** on RouterOS is the CLI/REST surface for MNDP results - WinBox's "Neighbors" tab is an MNDP listener - Any agent implementing device discovery for MikroTik equipment needs MNDP - The protocol is simple enough to implement from scratch — no library needed ## Protocol Basics | Property | Value | |----------|-------| | Transport | UDP | | Port | 5678 | | IPv4 | Broadcast to 255.255.255.255:5678 | | IPv6 | Multicast to ff02::1 (all-nodes link-local) | | Direction | Bidirectional — same port for send and receive | | Authentication | None — read-only discovery, no credentials | | Scope | Layer 2 broadcast domain (does not cross routers) | ## How Discovery Works 1. **Listener sends a refresh packet** — a small UDP datagram to 255.255.255.255:5678 (MAC-Telnet sends a minimal 4-byte zeroed header; a 9-byte form also works — see below) 2. **All RouterOS devices on the LAN reply** — each sends a TLV-encoded announcement with identity, version, board, MAC, IP, uptime, etc. 3. **Replies arrive asynchronously** — devices respond within milliseconds to seconds depending on network conditions 4. **RouterOS devices also announce periodically** (~60s cycle) without being prompte...