Various example embodiments for supporting firewalling of traffic are presented. The support for firewalling of traffic may include support for firewalling of layer-2 traffic (e.g., applying firewall rules to layer-3 traffic embedded within layer-2 frames) using a layer-2 firewall. The firewalling of layer-2 traffic by a layer-2 firewall may include support for firewalling of layer-2 traffic associated with various types of layer-2 services. The firewalling of layer-2 traffic by a layer-2 firewall may include support for firewalling of layer-2 traffic for which the layer-2 destination address of the traffic is known and layer-2 traffic for which the layer-2 destination address of the traffic is unknown. The firewalling of layer-2 traffic by a layer-2 firewall may include receiving, by a router, a packet of a flow of a layer-2 service and supporting, by the router, layer-2 firewalling of the packet at the router while honoring layer-2 forwarding of the packet at the router.