386.4 on my RT-AX56U completely shagged wireless communication with my printer (canon MP640)

[John Titor]

So..

I know this isn't going to be very helpful (yet). But i've just spent about 3 hours on troubleshooting this shirte and i'm in no mood to dig into this issue any deeper (yet).

Tl;Dr.: My (admittedly, very old) canon MP640 completely stopped working with the asuswrt-merlin 386.4 update. I could not figure out exactly why, but it was definitely related to the update, as rolling back to 386.3_2 fixed the issue.
Now I know what the first question is going to be: "Did you factory reset after the update?".. No. I did not. It frankly is very difficult for me to justify an approximately 30 minute down-time to all the users on my network.. Although i will try to factory reset and set everything up again from scratch in a few days. Hopefully i'll find a time window where internet connectivity isn't needed..

But yeah.. Unfortunately, this is all I got for now. After upgrading to 386.4, communication between any client on the network (including the router itself) and the printer did not work. Or rather: There was some sort of communication going on. The printer received and accepted DHCP info. Therefore, the printer was listed as associated, authorized and authenticated..
But when trying to access the printers web-server, it would 99% of the time just time out. The other 1% of the time, parts of the site would load E X T R E M E L Y slowly and incomplete.
When trying to add the device, either via WSD or TCP/IP, windows would never find it.
Nothing in the logs indicated dropped traffic. As a matter of fact, the router firewall isn't even turned on.
AIProtection ALSO didn't indicate any traffic being blocked, but i completely disabled it anyways for testing. It still did not work..

Reverting to 386.3_2 completely fixed the issue.

 

[eibgrad]

Please remove the release icon from your post. That's only intended for developer and/or script writers announcing any new releases, NOT because you happen to have a problem w/ that release.

I completely understand the hardship of bringing down the router for a clean upgrade, but as I stated in the last paragraph below ...

If I upgrade to latest version of merlin will all scripts etc still work

i'm on 386.3 of merlin at the moment but i spent forever trying to setup scripts in /jffs/scripts which are currently working well . if i update to 386.4 will these scripts disappear or stop working ?

www.snbforums.com

To restate, there's NO POINT in updating just for the sake of updating! If there's something critical, a known vulnerability that needs addressing, etc., that another story. But it's exactly problems like this that should have some ppl questioning their decision about if and when to update, particularly if they don't have the time to do it correctly. Better to leave well enough alone until you do.

 

[John Titor]

Sorry about the wrong tag! I have fixed that now..

Well. You do have a point about not updating at all. But then again, countless vulnerabilities have been addressed and fixed.. I don't know..

 

[ColinTaylor]

Nothing in the logs indicated dropped traffic. As a matter of fact, the router firewall isn't even turned on.

Side note: You should never turn off the router's firewall unless your router is behind another firewall because...

But then again, countless vulnerabilities have been addressed and fixed..

One possible cause of slow or intermittent access to a device is a missing or incorrect DNS setup. Check that your printer's hostname resolves via DNS.