A method and arrangement for failure handling in a tree-structured communications network having interconnected edge nodes and switching nodes. VLANs may be established by using spanning trees to provide connectivity in case of a failure in the network. Emitters in the edge nodes periodically broadcast alive messages on the VLANs, and notifiers note the alive messages. A missing alive message indicates a failure on one of the VLANs, and the notifier broadcasts corresponding failure messages on the VLANs. When the alive messages are restored, the notifier broadcasts corresponding repair messages. If a notifier fails to note a failure, one of the edge nodes performs a similar function although somewhat slower.