What's new

Bug report - RT-AC66U

  • SNBForums Code of Conduct

    SNBForums is a community for everyone, no matter what their level of experience.

    Please be tolerant and patient of others, especially newcomers. We are all here to share and learn!

    The rules are simple: Be patient, be nice, be helpful or be gone!

admax

New Around Here
I have an ASUS RT-AC66U-B1 WiFi AP with AsusWrt-Merlin version 386.3_2
I have a central router (Mikrotik) and this router is connected to the AP's of the house.
I use the AP to provide two wireless connectivity: one for the family and one for the guests.
The former is served in untagged packets, the guests are connected over the wired network with tagged packets, where the VLAN ID is 526.
This setup works well with other devices (I have more than one AP), but it does not work with ASUS.
I used to use the ASUS device as an AP (no routing functionality).

I have the following setup:

Code:
admax@RT-AC66U_B1-A8F0:/tmp/home/root# brctl show
bridge name    bridge id    STP enabled    interfaces
br0    8000.1831bfe4a8f0    no    vlan1
    eth1
    eth2
br1    8000.1831bfe4a8f0    no    vlan526
    wl0.1
admax@RT-AC66U_B1-A8F0:/tmp/home/root# ifconfig
br0       Link encap:Ethernet  HWaddr 18:31:BF:E4:A8:F0
          inet addr:[CENSORED]  Bcast:[CENSORED]  Mask:255.255.252.0
          UP BROADCAST RUNNING ALLMULTI MULTICAST  MTU:1500  Metric:1
          RX packets:733871 errors:0 dropped:0 overruns:0 frame:0
          TX packets:148254 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:100585703 (95.9 MiB)  TX bytes:15080592 (14.3 MiB)

br1       Link encap:Ethernet  HWaddr 18:31:BF:E4:A8:F0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:41659 errors:0 dropped:0 overruns:0 frame:0
          TX packets:58 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:5915875 (5.6 MiB)  TX bytes:6612 (6.4 KiB)

eth0      Link encap:Ethernet  HWaddr 18:31:BF:E4:A8:F0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:865513 errors:0 dropped:0 overruns:0 frame:0
          TX packets:345427 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:331947878 (316.5 MiB)  TX bytes:58798812 (56.0 MiB)
          Interrupt:179 Base address:0x4000

eth1      Link encap:Ethernet  HWaddr 18:31:BF:E4:A8:F0
          UP BROADCAST RUNNING ALLMULTI MULTICAST  MTU:1500  Metric:1
          RX packets:27891 errors:0 dropped:0 overruns:0 frame:2216860
          TX packets:304803 errors:22 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:6418769 (6.1 MiB)  TX bytes:65020870 (62.0 MiB)
          Interrupt:163

eth2      Link encap:Ethernet  HWaddr 18:31:BF:E4:A8:F4
          UP BROADCAST RUNNING ALLMULTI MULTICAST  MTU:1500  Metric:1
          RX packets:36171 errors:0 dropped:0 overruns:0 frame:14737
          TX packets:487320 errors:43 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:9453161 (9.0 MiB)  TX bytes:103664109 (98.8 MiB)
          Interrupt:169

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING MULTICAST  MTU:16436  Metric:1
          RX packets:441327 errors:0 dropped:0 overruns:0 frame:0
          TX packets:441327 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:103101719 (98.3 MiB)  TX bytes:103101719 (98.3 MiB)

lo:0      Link encap:Local Loopback
          inet addr:127.0.1.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING MULTICAST  MTU:16436  Metric:1

vlan1     Link encap:Ethernet  HWaddr 18:31:BF:E4:A8:F0
          UP BROADCAST RUNNING ALLMULTI MULTICAST  MTU:1500  Metric:1
          RX packets:651377 errors:0 dropped:0 overruns:0 frame:0
          TX packets:261418 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:116248210 (110.8 MiB)  TX bytes:42362800 (40.3 MiB)

vlan526   Link encap:Ethernet  HWaddr 18:31:BF:E4:A8:F0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:40220 errors:0 dropped:0 overruns:0 frame:0
          TX packets:6864 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:5699426 (5.4 MiB)  TX bytes:686418 (670.3 KiB)

wl0.1     Link encap:Ethernet  HWaddr 18:31:BF:E4:A8:F1
          UP BROADCAST RUNNING ALLMULTI MULTICAST  MTU:1500  Metric:1
          RX packets:101031 errors:0 dropped:0 overruns:0 frame:2216860
          TX packets:246908 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:19249091 (18.3 MiB)  TX bytes:212641946 (202.7 MiB)

admax@RT-AC66U_B1-A8F0:/tmp/home/root# robocfg show
Switch: enabled
Port 0:   DOWN enabled stp: none vlan: 1 jumbo: off mac: dc:2c:6e:39:6d:66
Port 1:  100FD enabled stp: none vlan: 1 jumbo: off mac: c4:b3:01:c2:bc:75
Port 2:   DOWN enabled stp: none vlan: 1 jumbo: off mac: 00:00:00:00:00:00
Port 3:   DOWN enabled stp: none vlan: 1 jumbo: off mac: 00:00:00:00:00:00
Port 4:   DOWN enabled stp: none vlan: 1 jumbo: off mac: 00:00:00:00:00:00
Port 5: 1000FD enabled stp: none vlan: 1 jumbo: off mac: 18:31:bf:e4:a8:f0
Port 7:   DOWN enabled stp: none vlan: 1 jumbo: off mac: 00:00:00:00:00:00
Port 8:   DOWN enabled stp: none vlan: 1 jumbo: off mac: 00:00:00:00:00:00
VLANs: BCM5301x enabled mac_check mac_hash
   1: vlan1: 0 1 2 3 4 5t
   2: vlan2: 5t
526: vlan526: 0t 1t 2t 3t 4t 5t

admax@RT-AC66U_B1-A8F0:/tmp/home/root# nvram show |grep ifname |grep "^br\|^lan"
size: 54014 bytes (11522 left)
br0_ifnames=vlan1 eth1 eth2
lan1_ifname=br1
br1_ifnames=vlan526 wl0.1
br0_ifname=br0
lan_ifnames=vlan1 eth1 eth2
br1_ifname=br1
lan_ifname=br0
lan1_ifnames=vlan526 wl0.1

admax@RT-AC66U_B1-A8F0:/tmp/home/root# nvram show |grep ^vlan526
vlan526ports=vlan1 wl0.1
vlan526hwname=et0
size: 54014 bytes (11522 left)


Filtering the ethernet frames coming out from the ASUS AP, VLAN tagging seems to work only for a few minutes.
After a sufficiently long time (in this experiment after 4 minutes, but this period is not deterministic at all) tagging suddenly disappears.
You can see the output of Mikrotik packet sniffer below.
In the experiment I was pinging one of the devices on the untagged part of the network, which is different in IP range/pool.
Only the relevant part is shown: note that in the first line, VLAN tag is set to 526 -- there are plenty of similar packets beforehand, and this is the right behavior.
In the second line, though, VLAN tagging is missing -- there are plenty of similar packets afterwards -- this is faulty.
What happened between this two ethernet frames? I do not know.

141 time=141.392 num=142 direction=rx src-mac=1A:ED:77:00:9C:57 dst-mac=C4:AD:34:77:E2:4B vlan=526 interface=bridge src-address=192.168.131.172 dst-address=[CENSORED] protocol=ip ip-protocol=icmp size=102 cpu=2 fp=no ip-packet-size=84 ip-header-size=20 dscp=0 identification=24729 fragment-offset=0 ttl=64

142 time=142.392 num=143 direction=rx src-mac=1A:ED:77:00:9C:57 dst-mac=C4:AD:34:77:E2:4B interface=bridge src-address=192.168.131.172 dst-address=[CENSORED] protocol=ip ip-protocol=icmp size=98 cpu=3 fp=no ip-packet-size=84 ip-header-size=20 dscp=0 identification=52547 fragment-offset=0 ttl=64

Let me clarify, that the infrastructure setup works well with other devices (including an openwrt device) , so the problem is at the ASUS AP.
I do not plan to use ASUS in the future (it is unreliable), this post is intended to help the developers, if interested.
 
Asus never advertised VLAN's support on any consumer router. You are trying to make it work and it fails - this is not a bug.
 
I have made an experiment and it has resulted an interesting outcome.
Using the same hardware, I installed FreshTomato v2021.7 K26ARM USB AIO-64K firmware and it seems to work like a charm.
I have run an overnight test (for more than 12 hours) and no mistagging has occured.
I understand that ASUS never advertised VLAN support on this device, but Merlin seems to be faulty anyway, as other firmware provide the right functionality -- this is the reason I posted the bug here. If you are not interested, it is up to you.

During the 12++ hours experiement, the central Mikrotik router looked for untagged packets on the corresponding interface, and none has been detected.
 
Yes, new/different firmware gives new/different capabilities. Expected results.

That doesn't make other firmware faulty.

Manufacturers aren't expected to (and rarely do) provide all potential that their hardware may be capable of.

It is always up to the buyer to confirm fit for use.

A misunderstanding of the above does not constitute a bug.

RMerlin firmware fixes bugs and/or enhances existing features for specific Asus routers, along with some extras. It does not promise to include a Swiss army knife approach to what the underlying hardware can do.

You can buy a family Audi and flash it to make it a rallying car (pure firmware). Doesn't mean the stock car is defective.
 
I understand that ASUS never advertised VLAN support on this device, but Merlin seems to be faulty anyway, as other firmware provide the right functionality -- this is the reason I posted the bug here.

Asuswrt-Merlin also never had officially VLAN's support. You can call it missing functionality, but it's not a bug.
 

Sign Up For SNBForums Daily Digest

Get an update of what's new every day delivered to your mailbox. Sign up here!
Top