macOS Lacks Native STP Support | Generated by AI
Question: Does macOS support STP (Spanning Tree Protocol)?
Answer:
macOS does not natively support or implement Spanning Tree Protocol (STP). STP is a Layer 2 protocol primarily designed for network switches and bridges to prevent loops in Ethernet networks by exchanging Bridge Protocol Data Units (BPDUs).
- macOS devices function as end hosts (not bridges or switches by default), so they do not participate in STP—they neither send nor process BPDUs to act as STP bridges.
- Historical issues reported (e.g., delayed DHCP responses on Macs when connected to switches with STP enabled) stem from switches applying STP listening/learning delays to ports connected to Macs. These are resolved on the switch side by enabling features like PortFast, not by any STP capability in macOS.
- While macOS supports creating software bridges (e.g., for virtual machines or Internet Sharing, using the
bridgeinterface in BSD layer), these bridges do not enable or run STP. There is no built-in configuration or support for STP/RSTP/MSTP in macOS bridges. - Apple hardware like AirPort base stations (which include small switches) also do not support STP.
If you need STP in a bridged setup on macOS, third-party tools or virtualized switches would be required, but native support is absent.
References:
- https://discussions.apple.com/thread/3917712
- https://www.reddit.com/r/osx/comments/4vytnj/spanning_tree_protocol_stp_still_a_problem_w_os_x/
- https://vowe.net/archives/012469.html
- https://discussions.apple.com/thread/2143359