Bridge firewalled with use-ip-firewall=no

Hi, I’ve read several discussions on the forum where users misuse the use-ip-firewall setting and bridges. That’s not my case here, this is disabled and not wanted, but still the weirdest thing is happening as I get bridged traffic reach the forward table in the firewall!
For now I believe this must be a misconfiguration rather than a bug, but there’s so little config in bridges that I can’t figure what to try.

Platform:

  • board-name: CCR2004-16G-2S+


  • version: 7.14.3 (stable)


  • factory-software: 7.0.4

I’ve also tried 7.15rc2 and 7.13.5, same issue.
But I’m sure this problem did not exist in the past, about 1 or 2 years ago.

Config:
I only removed L3 and firewalling stuff, some ethernet interfaces.

/interface ethernet
set [ find default-name=ether9 ] name="ether9 (xxxx)"
set [ find default-name=ether10 ] name="ether10 (xxxx)"
set [ find default-name=sfp-sfpplus2 ] arp=disabled name="sfp-sfpplus2 (xxxx)"

/interface bridge
add arp=disabled frame-types=admit-only-vlan-tagged name=bridge port-cost-mode=short protocol-mode=none vlan-filtering=yes
add arp=disabled name=loopback protocol-mode=none

/interface bridge vlan
add bridge=bridge tagged="bridge,sfp-sfpplus2 (xxxx),ether1 (xxxx),ether4 (xxxx)" vlan-ids=10
add bridge=bridge tagged="bridge,sfp-sfpplus2 (xxxx),ether1 (xxxx)" vlan-ids=11
add bridge=bridge tagged="bridge,sfp-sfpplus2 (xxxx),ether1 (xxxx)" vlan-ids=12
add bridge=bridge tagged="bridge,sfp-sfpplus2 (xxxx)" vlan-ids=13
add bridge=bridge tagged="bridge,sfp-sfpplus2 (xxxx),ether1 (xxxx)" vlan-ids=14
add bridge=bridge tagged="bridge,sfp-sfpplus2 (xxxx)" vlan-ids=18
add bridge=bridge tagged="bridge,ether4 (xxxx)" vlan-ids=192

/interface bridge port
add bridge=bridge frame-types=admit-only-vlan-tagged interface="sfp-sfpplus2 (xxxx)" internal-path-cost=10 path-cost=10
add bridge=bridge frame-types=admit-only-vlan-tagged interface="ether1 (xxxx)" internal-path-cost=10 path-cost=10
add bridge=bridge frame-types=admit-only-vlan-tagged interface="ether4 (xxxx)" internal-path-cost=10 path-cost=10
add bridge=bridge frame-types=admit-only-untagged-and-priority-tagged interface="ether3 (xxxx)" internal-path-cost=10 path-cost=10 pvid=11
add bridge=bridge frame-types=admit-only-untagged-and-priority-tagged interface="ether9 (xxxx)" internal-path-cost=10 path-cost=10 pvid=13
add bridge=bridge frame-types=admit-only-untagged-and-priority-tagged interface="ether10 (xxxx)" internal-path-cost=10 path-cost=10 pvid=13
add bridge=bridge interface="ether6 (xxxx)" pvid=11

/interface vlan
add interface=bridge name=vlan10 vlan-id=10
add interface=bridge name=vlan11 vlan-id=11
add interface=bridge name=vlan12 vlan-id=12
add interface=bridge name=vlan13 vlan-id=13
add interface=bridge name=vlan14 vlan-id=14
add interface=bridge name=vlan15 vlan-id=18
add interface=bridge mtu=1480 name=xxxx vlan-id=192

/ip settings
set rp-filter=strict secure-redirects=no

/ipv6 settings
set accept-redirects=no accept-router-advertisements=no

/ip firewall connection tracking
set enabled=yes loose-tcp-tracking=no udp-timeout=10s

Issue:
The problem is with three members of the bridge: ether9, ether10, and sfp-sfpplus2
They are tied to vlan 13, tagged on the SFP and untagged on others.
Also there is a vlan13 vlan interface on top of the bridge for routing, as this box is the gateway for 13.

:smiley: Communication between ether9 and ether10 seem to be bridged properly and do not go through the firewall. Bridge ports even have the HW offload.
:frowning: But all flows between sfp-sfpplus2 and those two other ports will hit the firewall. Logs show the same input and output interface :

 12:24:24 firewall,info BROKEN forward: in:vlan13 out:vlan13, connection-state:new src-mac xx:xx:xx:xx:xx:xx, proto TCP (SYN), 10.x.x.x:39274->10.x.x.x:443, len 60

What I’ve checked:

  • use-ip-firewall=no of course


  • no IP or MAC conflict


  • no interface with arp proxy


  • disabling vlan interface vlan13 does not fix it


  • /interface/bridge/host looks good

I’m considering downgrading even further but that’s inconvenient at the moment.

What would you suggest checking? Am I doing anything wrong?
How likely can this be a bug given that sfp-sfpplus2 is a CPU port without a switch chip?

Thanks a lot folks
Have a great day