BNC\DSL and related networking issue

I have a BNC peer to peer network and DSL.
1 router w/built in DHCP and 1 Hub.
I need to be on the network and DSL at the same time. With everthing hooked up I loose reliable connection with 3 of the PC’s. Unhook the hub and the network work perfect.
The hub and router are known good. All nic’s are known good. The 3 PC’s used to belong to the same person and ping will loopback on all 3 when you ping the original name from each PC.