Posted: Sun Feb 07, 2021 1:16 Post subject: bridged VAP on R6400v2
Bridged VAP has been broken since 2018 and I have just confirmed that it is still broken in the latest build. There are a number of workarounds for this, but I find that none of them work consistently.
I was thinking to flash an old version on my R6400v2, from a time when bridged VAP was working. However, the install guide says not to use any builds prior to 36995, when bridged VAP was already broken. The oldest build for the R6400v2 is 36104, but I don't think that is old enough for bridged VAP to work, plus it seems rather dangerous to ignore the install guide.
Is anyone aware of an older build that can be flashed on a R6400v2 that has bridged VAP working? Thanks.
As I mentioned, I have tried all of the workarounds and find that none of them consistently solves the problem. Sometimes they work, mostly they don't. I even tried the one that uses a different version of wlconf, not listed in that link.
I also played around with this for a while, manually adding and removing the VAP to/from a bridge using brctl. The moment I add it to a bridge, the VAP stops authenticating, even if the bridge has nothing else bound to it. Interestingly, if a client is already authenticated to the VAP while it is unbridged, it remains associated and functions fine once it is bridged. I am at a loss to explain why bridging a VAP would cause this behavior.
The only reasonable solution is to move back to a build where bridged VAP works. I am afraid there is no such build for the R6400v2.
I have tried builds 36995, 41328, 43192, and 45677. I reset to factory default and erased nvram before and after each upgrade. I then manually re-entered the configuration.
Build 45677 most consistently functioned using the workarounds. But once I added additional configuration, 3 vlans and 2 bridges, it stopped working. There seems to be a correlation between configuration complexity and this problem. Perhaps with more vlans and bridges, the sequence of device creation/configuration upon boot changes and something goes amiss. I will play around with it a bit more before giving up.
I got this working. Here is what I did and what I discovered in the process.
I started with a clean, nvram erased, 41328 build and slowly implemented my configuration, taking a snapshot of nvram after each step so that I could diff the changes. Here were the planned steps:
1. Add three 2.4 GHz VAPs and three 5 GHz VAPs with the VAP workaround in the startup script.
2. Add three VLANs.
3. Add two bridges.
4. Assign the bridges.
After I finished step (3), VAP stopped working. I diffed nvram between (2) and (3) and discovered that the act of adding the two bridges wrote a bunch of WLAN configuration data to nvram. I looked over the changes and saw two particular items that I remember reading in one of the threads concerning this issue: values were set for eth1_hwaddr and eth2_hwaddr. I checked with ifconfig that they were correct, but deleted them and rebooted. After that VAP started working again.
Certain changes to the configuration cause these values to be rewritten, so they need to be constantly deleted. It appears that these parameters are used before the startup script is run, so I put the following in the shutdown script:
):