Asus Merlin Media-Bridge Mode Bug

[DocUmibozu]

Hi,
the media-bridge operation mode is seriously bugged in merlin firmware.
Any value you insert in lan settings is not read and used by the bridge.
Also the bridge announces itself as a DHCP server, confusing the devices on the lan.
Asus firmware is ok.

 

[ColinTaylor]

Router model?
Firmware version(s)?

 

[DocUmibozu]

Router model?
Firmware version(s)?

Right, my fault.

AX68U and AX56U
firmware 386.7 and 386.5_2

I include a screenshot of the lan settings that both merlin firmware ignores. Infact you have to push a route command via ssh to make the router connect to the gateway on 192.168.1.1
Asus firmware is ok.

 

[ColinTaylor]

I suggest that you try stepping back through previous firmware versions until you find one that works properly. That will help RMerlin identify and fix the problem.

 

[MysticGold04]

I have routers that are running media bridge mode from both versions, 386.5_2 and 386.7 with no issue. (AC68u and AC3100). I would suggest a WPS reset and then setup manually again. It should allow you to use dhcp or static IP address for the router during setup.

 

[tartarmartyr]

I am running a RT-AC86U as router with a RT-AC68W as bridge, both running 386.7_2 (and both recently upgraded from the prior version) exhibiting the same issue. I actually noticed this issue several months ago, early in 2022 and was likely running 386.4 or 386.5 at the time. I will attempt the WPS reset on both devices this weekend and see how it performs after that.

 

[Squall Leonhart]

This is a thing even on 386.11, disable the DHCP server from http://<mediabridgeip>/Advanced_DHCP_Content.asp

 

[DocUmibozu]

This is a thing even on 386.11, disable the DHCP server from http://<mediabridgeip>/Advanced_DHCP_Content.asp

I reverted to official Asus Firmware, which doesn't have the bug.
Anyway Merlin on a media bridge Is pretty useless.

 

[Squall Leonhart]

I reverted to official Asus Firmware, which doesn't have the bug.
Anyway Merlin on a media bridge Is pretty useless.

has less bugs otherwise than official firmware.

 

[L&LD]

RMerlin firmware on a Media Bridge isn't useless at all. As a last-chance effort, it is a backup router, ready to be deployed with the latest stable firmware possible (if needed, in an emergency).

 

[Squall Leonhart]

This is apparently a regression, was fixed previously in 384

RT-AC68P in Media Bridge Mode - DHCP/dnsmasq problems

Summary: I have have two Asus routers running Merlin firmware on a home network. One is in media bridge mode. The clients on the media bridge have issues getting the correct IP and gateway using DHCP. **** Main Router Asus 1900P running Merlin 384.7_2 Connects to WAN. Wired and wireless...

www.snbforums.com

@RMerlin
You reintroduced this issue in https://github.com/RMerl/asuswrt-merlin.ng/commit/78facc663a8d04ac101a0d60240c0530c94cc127

Last working would have been 384.18
First broken 386.1

From what i can tell though the fix was only ever required for the 68U, 86U isn't affected

 

[DocUmibozu]

has less bugs otherwise than official firmware.

Except for the nasty DHCP bug, which makes the media bridge mode useless.
Merlin firmwares are a one man job and there's no problem if some detail slips.
In this corner case the standard firmware is better (or was, maybe the bug was closed... I just don't want to waste time on a now working media bridge).

 

[JGrana]

I agree with @L&LD about the Merlin version being a bit better than stock. I ran Media Bridge quite a bit in my former house. I had some issues with the 160Mhz dropping down to 80Mhz (This is a good use case for 160Mhz). Using @Adamm ’s ChannelHog script I was able to keep the radio at 160Mhz. Also used ntpmerlin since I am a big fan of chrony.
None of this would have been possible with stock.

I am in a new house and now have my router on the top of my media center cabinet. I now use a TP-Link switch for all my media gadgets and use MOCA to go from the router to a shelf in a closet that has another TP-Link switch feeding a NAS box and 2 printers.

I do miss the Media Mode. It works quite well.

 

[DocUmibozu]

Sorry but I don't understand: the media bridge is a "dumb" device which receives the connection... How can you possibily need to set 160mhz bandwidth in it?

 

[chris.at]

I can confirm that media bridge tries to act as a dhcp server which isn't quite nice. I fixed it for my szenario with the following config on the media bridge (dnsmasq.conf.add with 1 line in it):

admin@bridge:/jffs/configs# cat dnsmasq.conf.add
no-dhcp-interface=br0

But of course it would be nicer if it wouldn't even start answering dhcp requests by itself (fixed in firmare)...

ASUSWRT-Merlin RT-AC68U 386.11_0

 

[DocUmibozu]

Well, in any case I'm happy that after 1 year and 2 months my bug claim has been confirmed.

 

[chris.at]

This is a thing even on 386.11, disable the DHCP server from http://<mediabridgeip>/Advanced_DHCP_Content.asp

Doesn't work (tried it before I made the conf.add file), will still answer dhcp queries and also ignore the range set on this page.

 

[Squall Leonhart]

Doesn't work (tried it before I made the conf.add file), will still answer dhcp queries and also ignore the range set on this page.

has worked for me

 

[DocUmibozu]

Doesn't work (tried it before I made the conf.add file), will still answer dhcp queries and also ignore the range set on this page.

Revert to standard firmware...as I did and suggested before.
Merlin is useless on a media bridge configuration.

 

[RMerlin]

I just checked on an RT-AX88U_PRO running 3004.388.4 beta 3, and the dnsmasq configuration is fine for me:

pid-file=/var/run/dnsmasq.pid
user=nobody
bind-dynamic
interface=br0
resolv-file=/tmp/resolv.conf
servers-file=/tmp/resolv.dnsmasq
no-poll
no-negcache
cache-size=1500
min-port=4096
bogus-priv
domain-needed
no-dhcp-interface=br0
address=/use-application-dns.net/
address=/_dns.resolver.arpa/
dhcp-name-match=set:wpad-ignore,wpad
dhcp-ignore-names=tag:wpad-ignore
dhcp-script=/sbin/dhcpc_lease
script-arp
edns-packet-max=1232

Is anyone experiencing issues on the 388.x firmware, or only 386?

John's original fix was more a workaround than a real fix, as it prevented dnsmasq from starting rather than having it just not provide DHCP service, which is how Asus has it implemented, at least in 388. That's why his fix was reverted by a GPL merge.