hi guy i have installed in tenda D301 a firmware Sagem F@ST2704N V1 17.01.4 DSL modem,
i have configured wifi and work greate , but when i try to configure pppoe , nothing not connect ,i delete also wan and wan6 for try to recreate new but now i dont know how to recreate wan and wan6 
someone can help me ??? thankz
Probably the easiest first step is to get LEDE back to factory settings...
SSH in to the router and run the following commands...
firstboot
reboot
Then, use the LEDE User Guide to help you configure LEDE...
i did do that and restart to configure , but nothing i also follow this guide https://www.youtube.com/watch?v=wy1QQ1XVeDA i watched at 0:59 to 2:00 repeat the same configurationbut nothing ,before of this, i install a pakage
opkg update
opkg install ppp kmod-pppoe ppp-mod-pppoe
for do that i connect the router under worked router.
i saw in switch menu , also if a cable of telephone is connect to port , tell me wan disconnected
how i spossible ???
As far as I remember, it is not trivial/possible to switch this modem into a bridge mode as it is locked down. Are you sure the modem is in bridged mode? If you want to use your router as a PPPoE client, the modem must be in a bridged mode.
Hmm, I did not have to create a new interface nor install new packages. The default LEDE comes with wan preconfigured to use DHCP, so just click Edit and then change the protocol from DHCP to PPPoE. Then I do not remember if I had to save it first or it displayed the the PPPoE setup right away right updater the Protocol drop down.
You absolutely do not need to do anything with the switch configuration to configure PPPoE.
Everything you need is in the LEDE User Guide (link posted above).
Take your time, and you should have no issues following it.
how can setup in bridge i try to read
https://openwrt.org/docs/user-guide/network/bridge-mode
but not explain nothing o_O how is possible ??
You would turn off DHCP, firewall, and wireless on the ISP device, and set its connection type to bridge.
Your router would then do all the work (DHCP, firewall, wireless), and the connection protocol for the WAN interface would be PPPoE.
i dont have isp device the tenda td 301 is device for adsl 2+( is mine )
http://tendacn.com/en/product/D301.html
you can see a back of router-modem
i have ------telephone line ------> tenda route td 301 -------> switch -------> many computer
with standar firmware is easy set user password and protocol and start surf
here is very fu... hell o_O
If you have no other device besides the Tenda, then you would not set up a bridge.
yeaaa i would connect in internet exist a mode ???? i try to create pppoE , because usally in standard firmware work with this protocol
but not work i use this guide for do that step by step https://www.youtube.com/watch?v=wy1QQ1XVeDA1 i watched at 0:59 to 2:00
Where did you get the firmware for the Tenda?
The D301 is not supported in LEDE, either in stable release or snapshot.
https://openwrt.org/toh/views/toh_fwdownload?dataflt[Brand*~]=tenda
The video is wrong...you don't need to set up a new interface called PPPoE.
You select Edit for the WAN interface, and in the General Setup tab, change the protocol to PPPoE, enter the PPPoE credentials, and that's it.
i used this is firmware
firmware Sagem F@ST2704N V1 17.01.4 DSL modem,