Unauthorised interface create in pppoe connection

I am running an ISP with arround 500 client. I use PPPoe for providing services to my client. My problem is I am observing some unknown pppoe interface created in PPPoe connection named pppoe-in1/pppoe-in2. one more thing sometimes this pppoe interface created in my ether12 port but I have no physical connection in my ether 12 port. When i clicked in this pppoe interface i got one of my client name in username tab but when i checked in PPPoe active connection he was not there. I have attached some screenshot for understanding my query .One More thing when i torch PPPoe-in1 interface I was getting client routers ip in src address . Please help me out for solving this problem Thanks in advance.

Open a New Terminal, issue

/interface export
/ppp export

And copy & paste it here.

What are the RouterOS and Firmware versions?

Thanks, Pukkita for your replay.

My router is CCR-1036-12G-4s (tile) Router OS version 6.32.1. I have made a pdf with the problem you can have a look there follwing the link https://drive.google.com/open?id=0B9R_3EXFv56LaGp4SWNKeG9DSHM

exported interface is here

/interface ethernet
set [ find default-name=ether1 ] name="ether1 WAN"
set [ find default-name=ether2 ] name="ether2 LAN"
/interface pppoe-server
add name=pppoe-in1 service="" user=biplob768
add name=pppoe-in2 service="" user=mamun428
/interface vlan
add interface="ether1 WAN" l2mtu=1576 name=BDIX vlan-id=1020
add interface="ether1 WAN" l2mtu=1576 name=GGC vlan-id=519
add interface="ether1 WAN" l2mtu=1576 name=INTERNET vlan-id=518
/interface wireless security-profiles
set [ find default=yes ] supplicant-identity=MikroTik
/interface pppoe-server server
add authentication=pap,chap disabled=no interface="ether2 LAN" max-mru=1500 \
    max-mtu=1500 one-session-per-host=yes
/interface pppoe-server
add name=pppoe-in1 service="" user=biplob768
add name=pppoe-in2 service="" user=mamun428

There lies the reason: those are two pppoe bindings, you can remove them, if those two users connect via ether2 as the rest, they will be served by the main pppoe server.

Thanks again for your quick replay, how can i remove them ??

Look in Interfaces, you’ll see them with type “PPPoE server binding”.

It has worked. Thanx a lot for your cooperation. I have a question to ask can you tell me why those two interfaces was under ether12 ,where there is nothing connected with ether12? @pukkita

Someone purposedly set them there, Server PPPoE Bindings are only set manually.

oka i got it .