Joined: 11 Apr 2010 Posts: 311 Location: San Francisco Bay Area
Posted: Sat Dec 23, 2017 0:47 Post subject: 5Ghz Wireless Repeater Bridge Between Two Asus RT-AC68Us
I have been struggling to get a wireless REPEATER BRIDGE working between a base station router / WAP connected to a cable modem and a remote WAP using both their 5Ghz radios in AC mode. I am using two Broadcom-based Asus RT-AC68U Version C1 routers each running DD-WRT v3.0-r31899 (04/24/17 - ftp.dd-wrt.com/betas/2017/04-24-2017-r31899/asus-rt-ac68u/asus_rt-ac68u-firmware.trx) firmware. I have followed the REPEATER BRIDGE wiki (https://www.dd-wrt.com/wiki/index.php/Repeater_Bridge) closely with the base station / WAP and the remote WAP configured in accordance with its directions. Internet access through the base station / WAP via 2.4Ghz WiFi works flawlessly but access through the 2.4Ghz WiFi remote WAP does not work at all. Even when the distance between the two routers is small, clients cannot get a DHCP allocated IP address from the remote WAP's 2.4Ghz WiFi nor can they get Internet service. Assigning a static IP address to my laptop and accessing the remote router's web configuration page over 2.4Ghz WiFi works intermittently which is equally baffling. I can get consistent access to the remote router with a static IP address defined on my laptop and working through wired Ethernet.
Is there a way for me to link the two routers together via the 5Ghz radio, tunnel the base station router's VLAN1 through it, and bridge that vlan to the remote router's VLAN1? I have done something similar in this thread (https://www.dd-wrt.com/phpBB2/viewtopic.php?p=907313#907313) and could use some help: Either to fix what mistakes I have made following the REPEATER BRIDGE wiki or to build up this function from CLI commands directly. I have been tearing my hair out on this one.
Joined: 18 Mar 2014 Posts: 12837 Location: Netherlands
Posted: Sat Dec 23, 2017 12:20 Post subject:
Problems with repeater bridge are twofold (at least), as @Ebgrad pointed out repeater bridge is a layer two bridge which uses ebtables to bridge the MAC addresses of your wireless with the rest.
MAC addresses are a mess they are sometimes the same for wireless and wired, and when making a VAP this sometimes gets the same MAC address. Yes you can set MAC addresses by hand and that is what can make it work.
The second problem is that in recent builds by BS there is compilation error which cause ebtables to hang.
Kong's builds does not have this problem (and if you have to use BS builds I have a newly compiled ebtables which you can use)
Joined: 11 Apr 2010 Posts: 311 Location: San Francisco Bay Area
Posted: Sat Dec 23, 2017 18:42 Post subject:
Thanks @egc,
My friend and I suspected as much due to the non-deterministic behavior we were seeing when trying to get this to work. Please note we are not defining any Virtual Interfaces on the 5Ghz radio and were trying to use the entire device for the bridge.
Please send me a link to your updated ebtables and any instructions you have to integrate into BrainSlayer builds. If it looks too hard, I will either switch over to a recent Kong release or go with the Powerline / MoCA Ethernet solution suggested by @eibgrad and be done.
3. Test to ensure that the uploaded 'ebtables' is working:
/tmp/root/ebtables -L
You should see some output as shown below:
Bridge table: filter
Bridge chain: INPUT, entries: 0, policy: ACCEPT
Bridge chain: FORWARD, entries: 0, policy: ACCEPT
Bridge chain: OUTPUT, entries: 0, policy: ACCEPT
4. If Step 3. is successful it means the 'ebtables' binary is working for your router. Proceed to override your router's existing binary with the uploaded one with the command below:
mount --bind /tmp/root/ebtables /usr/sbin/ebtables
That should do it. Do note though that the above will not survive a router restart as the ebtables binary is stored in the router's RAM. A restart will wipe it off. To make it persistent across router reboots, you need to upload the ebtables to a USB thumb drive or the JFFS partition in your router and add the command in Step 4. to your router's startup script, adjusting the path to the location of the uploaded ebtables binary.
But it is easier to use Kong's builds, be sure to erase nvram/reset to defaults and put settings in manually do not restore from a backup
Joined: 11 Apr 2010 Posts: 311 Location: San Francisco Bay Area
Posted: Sun Dec 24, 2017 16:20 Post subject:
Thanks, much appreciated.
I think I convinced my friend to pull a CAT6 cable. We found an easy pathway from the base station / WAP to the remote WAP. Much less headache. However, your instructions are very helpful if we decide to ever go that route.