Question about ASUS Merlin Media Bridge

[El_Don]

Hello all,

Please forgive the question if it's been answered elsewhere. Copious searching has not yielded an answer yet.

I've got 2 RT-AC3200 routers, both running 380.62_2. One is in "Wireless Router" mode and hooked up to one part of the network. The other is in "Media Bridge" mode and hooked up to a switch on a different part of the network.

The long and short of it is that it appears that I can only ever get 7 clients to be able to connect through the bridge. These systems have static IP addresses (e.x. 192.168.0.8) and they cannot ping the main router (192.168.0.1). However, up to 7 of the systems on the bridge router has no issue whatsoever. When I reboot the bridge, the particular clients that can connect change, but no more than 7.

I've looked through all of the packets as best as I can and it appears that, for those specific non-working systems, ARP responses never get answered. They do for the working systems (and again, this is subject to change after nothing more than a reboot of the Media Bridge router.) To take this equation out, I've manually assigned ARP entries for all of the devices on the entire network.

One thing that is curious is that since I have the router (0.1) broadcasting an SSID on 5Ghz-2 (second radio) and I have the bridge (0.3) acting as a media bridge using it's second radio as well and connecting to the main router wirelessly, I notice that the bridge appears to what may be spoofing of MAC addresses. ifconfig on the bridge shows that I've got wl2.1 through wl2.7. Wl2.1 appears to have the MAC address of VLAN1 while wl2.2 through wl2.7 appear to be MAC addresses of other devices on the network.

Does anyone understand on a technical level how the system accomplishes the "Media Bridge" functionality and if there is a way to sort of trick it into doing what I need it to do?

 

[Vexira]

normally its set and for get did you factory reset the u it before bridging it?

 

[El_Don]

Yes. Thank you for your reply!

 

[Vexira]

no biggie

 

[Vexira]

media bridge is supposed to be just set it to media bridge mode, then connect, id check to make sure the media bridge is the only connection to the router.

 

[Vexira]

if you have any more issues let me know

 

[El_Don]

Thanks for the reply! Yes, this was the case. I actually had every port except one LAN port get popped by lightning, but every other aspect of the router worked perfectly. So I had the one good port hooked up to a managed gigabit switch. Every time it would boot it would find 6 or 7 MAC addresses on the LAN and create wl2.1 wl2.2 wl2.3 .... wl2.7 with those spoofed MAC addresses. And it would change on every reboot.

I tried to figure out how it was creating them so I could possibly create more using a script. I tried the `ip link` route, using brctl, and any other method that would create a new entry for wl2.8. No dice, mostly because the network driver would not support the command. I think the limit is in the actual network controller driver where, for some reason, it maxes out at 7 clients. These are 100% for sure being created by the kernel as I found in the log: "kernel: register interface [wl2.1]" (and the same for 2-7).

I've solved this problem, although unfortunately for those of you finding this on a Google search, it was not a fix in software. I ended up spending a ridiculous amount of time and effort on running a cable. And I suggest that anyone else with this problem do the same. I have a relatively round understanding of networking principles and Linux administration (12+ years experience) and I wish I had just spent the 15 hours I poured into solving this problem in software by just running a cable instead.

Thank you Vexira for your interest and support! I appreciate it a lot.

 

[Vexira]

Ahhh so you spoof the router into thinking the switch was extra ports, and your welcome I'm the patron saint of unanswered threads lol. I'm glad to her it works.

 

[El_Don]

That is how the Media Bridge appears to work. It spoofs the "clients" on the wired portion of the network so it can do it's thing.

But a cable removed the media bridge from the equation so things can operate.

 

[Vexira]

Media bridge is actually just like a switch but it connects via wifi rather than a cable

 

[hookhook]

I used repeater mode. Only 4 clients are allowed to connect. Asus should indicate this limitation to user. Cheating customers!