Router problems

Hello
We are a cooperative sharing an Internet connection from TDC profession.
Connectivity is as follows:
ADSL modem > SE5880 Router (TDC's) > 16 ports Switch >
DSL modem> Router SE5880 (TDC's)> 16 port switch> Cables in each apartment.

TDC says that they can see there is full connectivity. The problem is that not everyone can get on the Internet, they have the network (full IP address, etc.). When I saw the same mains (which "does not work") in my notebook I get the right speed Internet connection.

One user has connected a wireless router-switch on its input cable in this opportunity, but when I run ipconfig in cmd, says his DNS suffix to be in my system ?

Where can the fault lie ?

The user who has set up its wireless line into the house, he has ensured safe connection to others can connect to? mac filters only numbers listed in the list can come in. it is not how you catch his box so it's the numbers you see.

I just can not see why I had to catch his box and get HIS DNS Suffix? He has just connected a router to plug him into the apartment, I sit on my own connection directly to the switch and router. I do not capture on his wireless.

But his connection to his jack "go back" and interfere with our other phobia transmission?

User who has set up its own router may have been disconnected from the Internet to his port 1 instead of the WAN, and if he does not have disabled its DHCP server in the router so that it will publish the IP addresses that may interfere with IP i get from internet router (SE5880). Try to ask the user who owns the wireless router to disconnect from and then see if it solves the problem after a computer is restarted.

This seems indeed to be the solution. It knew precisely that he had put into port 1-4 and not WAN, did not know that this could "destroy" the whole system. Thank you. java script:% 20void (0); Expect to get off the DHCP server in the router so that he can still use it as wireless Swicth.