In my case, I’ve experimented with the “WAN under Bridge” configuration in the past week on my RB5009. My WAN is a PPPoE connection over a SFP GPON module, which requires no VLAN tagging, so when I put sfp-sfpplus1 under the Bridge I set a dummy PVID 1000 for it with frame-types=admit-only-untagged-and-priority-tagged and configured th PPPoE connection to use the interface vlan1000 under bridge, everything seems to work fine. The bridge ports are all shown with the H-flag active and bridge-fast-path-active is on. My LAN only uses VLAN, the bridge interface with PVID 1 is not used (no IP address and DHCP). The router has no problem with WAN speedtest around 2-2.2Gbps (the limit of my line) for both IPv4 and IPv6.
However, I noticed that IPv4 Fasttrack doesn’t work anymore. All the dummy fasttrack rules are still listed under the tabs of the IPv4 firewall window in WinBox, but they all have counter == 0. Most of the IPv4 connections listed under the Connections tab do have the F flag active (fasttrack not greyed out in the status bar). But the counters are all 0:
Using “Profile” I could see that the “firewall” task now use about 3-4x more CPU, but the RB5009 can still handle everything without a problem. If I pull sfp-sfpplus1 out of the bridge and set PPPoE to use it, the fasttrack counters increase normally and the CPU usage for “firewall” drops.
Is this the Fasttrack inactive the intended behavior? According to http://forum.mikrotik.com/t/fastpath-fasttrack-l2hw-l3hw-clarification/155333/1 FastPath should be supported with VLAN filtering since 7.2 so this condition should still be met for Fasttrack, shouldn’t it?