RT-AC87U: Strange routing behaviour: Vlan tagging disables port1 and 5Ghz wifi

[Nigel Mahon]

Hello dear fellow SNB enthusiasts! I have a puzzle for you which is keeping me busy for quite some time.

I have an Asus RT-AC87U with the latest Merlin firmware. I'm using this on a (KPN) fibre connection with PPPoE configured. To provide my home with routed IPtv I have managed to configure this with JFFS scripts and configs. The router keeps up with the > 500/500mbits the fibre connection deliveres. Nice

So, in short, my problem:
- If I active the scripts on the JFFS partition, routed IPtv works like a charm.
- Port 1 on the 4 port internal switch does not work anymore.
- 5Ghz wifi does not work anymore, nor does the webinterface for basis wifi settings. Pro-settings do work, radio for both 2,4 and 5ghz is on. 2,4Ghz wifi works. The webinterface only shows the bottom part of the page and does not respond to input very well. Cannot scroll to the top, quite strange.

Good to know:
Vlan 6 = internet, and I have enabled it simply in the webinterface.
Vlan 4 = Tv and this is added in the Wan-start script, which runs nicely.
Vlan 7 = Voip, which I don't use.

To start, here is my wan-start script:

#!/bin/sh

# Leave VOIP traffic tagged for original router
# /usr/sbin/robocfg vlan 7 ports "0t 4t 7t"

# Setup VLAN4 on the CPU as well so we can talk to it
/usr/sbin/robocfg vlan 4 ports "0t 7t"
/usr/sbin/robocfg vlan 1 ports "4 3 2 1 7t"

# Add VLAN4 as a physical interface
/sbin/vconfig add eth0 4

# Request an IP-address and setup static routes

/usr/bin/killall udhcpc
sleep 1

udhcpc -i vlan4 --clientid-none -O msstaticroutes -O staticroutes -V IPTV_RG -s /jffs/scripts/vlan4.script -p /var/run/vlan4.pid -b -O33 -O249

# Restart IGMP proxy

sleep 20
/usr/bin/killall igmpproxy
sleep 1
/usr/sbin/igmpproxy /jffs/configs/igmpproxy.conf

And that kinda works well I'd say, since it does this to my robocfg:

admin@RT-AC87U-0600:/tmp/home/root# robocfg show
Switch: enabled
Port 0: 1000FD enabled stp: none vlan: 2 jumbo: off mac: 94:04:9c:db:ca:d9
Port 1:   DOWN enabled stp: none vlan: 1 jumbo: off mac: 00:00:00:00:00:00
Port 2:   DOWN enabled stp: none vlan: 1 jumbo: off mac: 00:00:00:00:00:00
Port 3: 1000FD enabled stp: none vlan: 1 jumbo: off mac: 80:fa:5b:26:63:71
Port 4:   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: 1 2 3 4 7t
   2: vlan2: 0 7
   4: vlan4: 0t 7t
   6: vlan6: 0t 7t
1045: vlan1045: 2 3t 7
1046: vlan1046: 3t 5 7t 8u
1047: vlan1047: 0 3t 8t
1099: vlan1099: 3 4t
1100: vlan1100: 1t 5t
1101: vlan1101: 4 7 8u
1102: vlan1102: 1t 2 3 4t 5t 8u
1103: vlan1103: 1 2 3 4t 5t

I have tried various port-settings, since port 1 AND 5Ghz wifi doesn't work when this is active I think it has something to do with each other. But not sure.

The output of brctl show us this:

admin@RT-AC87U-0600:/tmp/home/root# brctl show
bridge name     bridge id               STP enabled     interfaces
br0             8000.9c5c8eb70600       yes             vlan1
                                                        eth1
                                                        wl0.1

Did I just found a great bug, or made a big mistake? Thanks for thinking this one through with me!

Further config info about the scripts can be found here (Dutch site, but the scripts are English), if needed I'm more then happy to eleborate. Crazy amounts of logs can be found here.

 

[john9527]

Port 1 on the 87U is 'special' and is indeed tied to the 5GHz Quatenna radio. If you do a search, I'm sure you can find numerous posts talking about it. My advice, don't change the port 1 default configuration.

 

[Nigel Mahon]

Port 1 on the 87U is 'special' and is indeed tied to the 5GHz Quatenna radio. If you do a search, I'm sure you can find numerous posts talking about it. My advice, don't change the port 1 default configuration.

Thanks! That confirms my gut feeling, but I have not found out how to isolate port 1 from the vlan settings set in my scripts. How would I not change the config?
I have no excluded port 1 from the vlan 4 associating but this doesn't work in terms of fixing my issue.

Edit: fixed it by removing this from the config:
# /usr/sbin/robocfg vlan 1 ports "1 2 3 7t"
Didn't need it anyway.

I also noticed the logical numbering of ports is inverse from the fysical numbering on the router. Port1 in fact port4 on the outside of the device.

Anyway, thanks - u gave me exactly the right nudge to find the solution!

 

[john9527]

I'll have to let one of the other experts on VLAN tagging step in from here. I was just hoping to save you some frustration in that there is indeed something unique about that port.

 

[Nigel Mahon]

I'll have to let one of the other experts on VLAN tagging step in from here. I was just hoping to save you some frustration in that there is indeed something unique about that port.

And u did - I editted my message: It is solved, thanks to your hint in the right direction

 

[vfrvulcan]

I have the same problem with WiFi 5GHz being disabled but I'm not using VLANs.

Using 380.64 on the RT-AC87U I followed this Transmission...for Asuswrt/Merlin post to configure Transmission to route via OpenVPN.

All appeared to be working but then there was a spontaneous reboot of the router. When it came back up I noticed the 5GHz LED was off, went to the admin and found the same incomplete page for WiFi with no option to do a lot and cannot enable 5GHz. I knew about the 'special' problem so don't have anything in LAN port #1. EDIT: Just pulled the cable from #2 and put it into #1 and it's working fine, but still no WiFi 5GHz.

I hadn't set the VPN to start with WAN as I was just checking if I could get it working. I decided to upgrade to 380.65b3 but unfortunately I still have the same issue

Any pointers would be helpful, and sorry if I've hijacked this thread but the initial symptoms are identical.

 

[Nigel Mahon]

Hi vfrvulcan, I know the feeling - really annoying if you know your config is good but still it doesn't work - maybe because of some strange connection between a lan port and the 5ghz wifi adapter.

I can't help u with your problem other then repeating john9527's advice: seek for a configuration where port 1 does not get included in changes. That's the only thing I managed to do: not fiddling around with the lanport vlan assignments.

 

[vfrvulcan]

Hi vfrvulcan, I know the feeling - really annoying if you know your config is good but still it doesn't work - maybe because of some strange connection between a lan port and the 5ghz wifi adapter.

I can't help u with your problem other then repeating john9527's advice: seek for a configuration where port 1 does not get included in changes. That's the only thing I managed to do: not fiddling around with the lanport vlan assignments.

Thanks Nigel,

But as I said, my issue has the same symptoms as yours but was not triggered by modifying any configuration for port #1 - indeed, as I state, port #1 still works. WiFi 5GHz doesn't and neither does the WiFi page in the router config.

 

[sfx2000]

Port 1 on the 87U is 'special' and is indeed tied to the 5GHz Quatenna radio. If you do a search, I'm sure you can find numerous posts talking about it. My advice, don't change the port 1 default configuration.

LAN1 and 5GHz are managed by the QTN on the RT-AC87U - so be mindful of this...

Keep your designated VLAN TagID's above 10, as those below may, and often are, used internally by the BHR vendor... (not just Asus, but others)

My preference and recommendation is to keep private VLAN's above 100, just to be sure - not like they're getting scarce or anything...