Cannot assign port 4 to WAN on TP-Link WR740N by DD-WRT wiki

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http://serverfault.com – I'm following the DD-WRT instruction to get TP-Link WR740N v3's Port 4 on a different VLAN, but this doesn't happen. First, I have no "Setup > VLANs" settinngs tab in DD-WRT v24-sp2 (07/20/12) std r19519. I can get Internet on Wi-Fi if assigning eth1 to "WAN Port", but then all Ethernet ports get on the same VLAN and any wired connection grabs the DHCP address and Internet connection from router. When following the "old" instruction, if I run, say, nvram set vlan2ports="2 5*", should there appear a new interface, vlan2, in ifconfig, after ifconfig vlan2 up? It doesn't - does it mean there (HowTos)