If you want to use the gray (DSL) port as ethernet WAN port than you can add the followig code
(but of course it is an example you can change the MAC etc.)
config switch_vlan
option device 'switch0'
option vlan '2'
option ports '4 6t'
config device 'ethwan_dev'
option name 'eth0.2'
option macaddr '02:26:33:51:69:02'
config interface 'wan_eth'
option proto 'dhcp'
option ifname 'eth0.2'
option auto '1'
config interface 'wan6_eth'
option ifname '@wan_eth'
option proto 'dhcpv6'
option reqaddress 'try'
option reqprefix 'auto'
option auto '1'
If you want to separate an single Yellow port for example as WAN Port use the following code
Port 3 means the port next the USB and power connector.
(it use vlan 7 and eth0.7 for example but the next free is normally 6)
config switch_vlan
option device 'switch0'
option vlan '7'
option vid '7'
option fid '7'
option ports '0t 6t'
config switch_vlan
option device 'switch1'
option vlan '7'
option ports '3 6t'
config device 'port3_dev'
option name 'eth0.7'
option macaddr '02:26:33:51:69:07'
config interface 'wan_eth'
option proto 'dhcp'
option ifname 'eth0.7'
option auto '1'
config interface 'wan6_eth'
option ifname '@wan_eth'
option proto 'dhcpv6'
option reqaddress 'try'
option reqprefix 'auto'
option auto '1'
and of course you must remove port 3 from eth0.1:
config switch_vlan
option device 'switch1'
option vlan '1'
option ports '0 1 2 6t'
If you want a tagget VLAN 8 on Port 3 of the yellow switch. this should work:
config switch_vlan
option device 'switch0'
option vlan '8'
option vid '8'
option fid '8'
option ports '0t 6t'
config switch_vlan
option device 'switch1'
option vlan '8'
option vid '8'
option ports '3t 6t'
What I have not succeeded so far a tagget VLAN with vid = 100 but on eth0.9 or so.
And i have not really understand the meaning of FID.