WLAN disabled when I plugin WAN

[gulliverrr]

I have an ASUS WL-520GU running KAMIKAZE (bleeding edge, r12857) - no GUI - for some years now with no problems. I was using it as an AP with wired uplink and 3 other wired devices as a switch all in the LAN ports. WAN port was not used. DHCP was running on another machine at the uplink side. No VLANs are needed anywhere whatsoever.

I now need one more wired device (so 4+1=5) but as soon as I plug in anything on the WAN port, the WLAN stops. At least the SSID stops being broadcasted and wirelessly connected devices, get disconnected.
I tried most sensible changes from SSH (remember, no GUI/Web interface) to put/bridge everything together or disable WAN with no success.
A colleague recalled another identical issue with a cheap TP-Link (TL-WR741ND) from the past that had this weird limitation that reached a dead end, so I thought about asking you in case I'm trying to make something impossible.
Here is some of my configuration:

root@OpenWrt:~# cat /etc/config/network
#### VLAN configuration
config switch eth0
        option vlan0    "1 2 3 4 5*"
        option vlan1    "0 5"


#### Loopback configuration
config interface loopback
        option ifname   "lo"
        option proto    static
        option ipaddr   127.0.0.1
        option netmask  255.0.0.0


#### LAN configuration
config interface lan
        option type     bridge
        option ifname   "eth0.0"
        option proto    static
        option ipaddr   10.10.10.200
        option netmask  255.255.255.0
        option gateway  10.10.10.254
        option dns      10.10.10.254


#### WAN configuration
config interface        wan
        option ifname   "eth0.1"
        option proto    dhcp

and wireless:

root@OpenWrt:~# cat /etc/config/wireless

config 'wifi-device' 'wl0'
        option 'type' 'broadcom'
        option 'channel' '7'
        option macfilter 'deny'
        list maclist 'B4:E6:2A:79:11:8B'


config 'wifi-iface'
        option 'device' 'wl0'
        option 'network' 'lan'
        option 'mode' 'ap'
        option 'ssid' 'BOB'
        option 'encryption' 'psk2'
        option 'key' '123123123'
        option macfilter 'deny'
        list maclist 'B4:E6:2A:79:11:8B'

Any advice is welcome

[mk24]

The only change needed here is to put all 5 switch ports into the same VLAN. I'm not sure what the syntax is to do that on such an old version.

This is different from the TL-WR741. On those the WAN port is a dedicated CPU port it does not go through the switch.

[gulliverrr]

Thank you @mk24 !
Read a bit more and ended up with this change:

root@OpenWrt:~# cat /etc/config/network
#### VLAN configuration
config switch eth0
        option vlan0    "0 1 2 3 4 5*"
        option vlan1    "0 1 2 3 4 5*"


#### Loopback configuration
config interface loopback
        option ifname   "lo"
        option proto    static
        option ipaddr   127.0.0.1
        option netmask  255.0.0.0


#### LAN configuration
config interface lan
        option type     bridge
        option ifname   "eth0.0 eth0.1"
        option proto    static
        option ipaddr   10.10.10.200
        option netmask  255.255.255.0
        option gateway  10.10.10.254
        option dns      10.10.10.254


#### WAN configuration
#config interface       wan
#       option ifname   "eth0.1"
#       option proto    dhcp

Will test for a few days and come back here to mark this as answered.

[gulliverrr]

Hmm I've been getting intermittent connectivity issues, that is machines on the uplink side couldn't ping 10.10.10.200 and machines on the WiFi of this router couldn't ping machines on the uplink side. Rebooting the main DHCP machine on the uplink side and clearing arp was not affecting anything. WiFi SSID was not disappearing at least.
I changed to (removing VLAN1):

root@OpenWrt:~# cat /etc/config/network
#### VLAN configuration
config switch eth0
        option vlan0    "0 1 2 3 4 5*"

#### Loopback configuration
config interface loopback
        option ifname   "lo"
        option proto    static
        option ipaddr   127.0.0.1
        option netmask  255.0.0.0


#### LAN configuration
config interface lan
        option type     bridge
        option ifname   "eth0.0"
        option proto    static
        option ipaddr   10.10.10.200
        option netmask  255.255.255.0
        option gateway  10.10.10.254
        option dns      10.10.10.254


#### WAN configuration
#config interface       wan
#       option ifname   "eth0.1"
#       option proto    dhcp

But I still get the same issues.
I'm not sure if this syntax has a mistake (should 5 be included too?).

config switch eth0
        option vlan0    "0 1 2 3 4 5*"

[gulliverrr]

I can confirm above configuration is working after all for some days now with no problem.
I suspect something was getting cached (arp, dhcp lease) that was causing some strange behaviour. After changing openWRT config, before rebooting the machine, I reboot first the main router (DHCP server), then a power line adapter (for my basement) and then the openWRT machine and everything was working great (lan inter-connectivity, internet connectivity and correct DCHP range assigned).
I mark above as the solution for simplicity although credits go to mk24.