My question is : can i set 2 PPPoE client in 1 interface? If yes, what configuration I need?
Thanks
some people try to use MetaRouter for that…
And you need it for… 
I have 2 PPPoE account and need to use them Simultaneously. just this
Still didn’t explain WHY do you need them.
But if you want an answer in the same level as the question… well…
inet cable → switch → Router (2 interfaces, 2 PPPoE) → LAN.
DOOH!
first thanks for your attention , I tell you more: I need 1.5 Mbps bandwidth and for some reason my isp can not give me this in one Account and they divided it to 1 Mbps and 512 Kbps.
Your ISP has an ID 10 t error. Usually found between users chair and keyboard, but in this case - your ISPs “admins” chair and keyboard 
Try to change ISP, if not possible - talk to a higher manager, not that “techsupport”.
Have you mentioned your routerboards model?
I’m using RB433 and have wireless bridge with my ISP, unfortunatly where I’m using my radio, just this ISP is available. I also spoke with the higher person there, but they said they are using a management program tha have these bandwidth as series: 64k 128k 256k 512k 1024k 2048 k and so on! 
Take those 2048k!
That is a common pokemon special-power - to find problems where are none!
P.S. Your ISP is talking about some stupid webpanel. In reality they can give you bit by bit exact speed.
Ok I think its enough. thanks
yeah, bafh really has an error in DNA…
sorry for the offtop, but he’s the first such an aggressive thing on the forum over last years…