Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

FS#3996 - edgerouter-x DSA switch does not forward bridge-in-bridge packets correctly #9031

openwrt-bot opened this issue Aug 29, 2021 · 2 comments


Copy link

openwrt-bot commented Aug 29, 2021


If a vlan-aware bridge is configured for the build-in ethernet ports, and a vlan-interface on that bridge is then put into a different bridge (to include wifi radios for example), then frames between tagged and untagged ethernet ports of the edgerouter x are not forwarded correctly.

Example setup:

┌────┐ ┌────┐ ┌────┐ ┌────┐ ┌────┐ │eth0│ │eth1│ │eth2│ │eth3│ │eth4│ └─┬──┘ └─┬──┘ └─┬──┘ └─┬──┘ └─┬──┘ 2 2 2 2t 2t ┌┴──────┴──────┴──────┴──────┴─┐ ┌─────┐ ┌─────┐ │ bridge1 │ │wlan0│ │wlan1│ └─────────┬───────────┬────────┘ └─┬───┘ └─┬───┘ │ bridge1.4 │ │ │ └────┬──────┘ │ │ └─────────────┐ ┌───┘ │ ┌─┴───┴─┐ │ │bridge2├───────────┘ └───────┘ config device 'bridge1' option name 'bridge1' option type 'bridge'

config bridge-vlan 'bridge1_2'
option device 'bridge1'
option vlan '2'
list ports 'eth0:'
list ports 'eth1:
list ports 'eth2:*'
list ports 'eth3:t'
list ports 'eth4:t'

config device 'bridge2'
option name 'bridge2'
option type 'bridge'
list ports 'bridge1.2'

config interface 'lan'
option proto 'static'
option ipaddr ''
option device 'bridge2'

In the above configuration, frames between Ethernet port eth0 (vlan2 untagged) and port eth4 (vlan2 tagged) are not forwarded. Interestingly, the router itself is able to reach devices connected to eth0 and eth4, when pinging on the 'bridge2' interface.

Frames between untagged ports (e.g. eth0 and eth1) are forwarded correctly and frames between tagged ports (eg. eth3 and eth4) are forwarded correctly.

Also, tagged frames are incorrectly forwarded on untagged ports, so it is possible to reach a device connected to eth3 (tagged) on eth2 (tagged).

This issue does not appear, if the 'bridge1.4' interface is configured without an additional bridge, so the second bridge seems to be interfering with the hardware offloading.

Copy link

openwrt-bot commented Aug 29, 2021


Possibly related:

Copy link

openwrt-bot commented Aug 29, 2021


I have tested this patch, and it does fix the issue, as already suspected.
Therefore, I have created a backport for kernel 5.4 and submitted a pull request: #4493

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
None yet

No branches or pull requests

1 participant