Can all PPP-based tunnels be bridged on the router?

• A. Yes
• B. No
• C. Only some
• D. Depends on the firmware

Answer: (A)

Bridging on RouterOS works by combining interfaces into a single Layer 2 domain, so a PPP-based tunnel interface can be treated like any other Ethernet-like port. Because these tunnels create their own virtual interfaces at Layer 2, they can be added to a bridge just as a physical port would be. Once bridged, frames can move transparently between the LAN ports and the remote end of the tunnel, making devices on the local network appear as if they’re on the same broadcast domain as the remote side.

In practice, you can bridge common PPP-based tunnels such as PPTP, L2TP, or PPPoE tunnel interfaces. Just keep in mind overhead from encapsulation can affect MTU, and ensure the bridge setup matches your network goals to avoid unintended traffic flooding or loops. That’s why the best choice is that all PPP-based tunnels can be bridged on the router.