I am using rdmacm to setup the connection between two hosts.
One problem I have is that the two hosts are connected through TCP/IP interfaces in the same subnet, but the RDMA interface is a different interface. Is it possible to use rdmacm to initialize the socket connection with the TCP/IP interface but use the other interface for RDMA?
Not sure what do you mean? What protocol are we talking about? What card are you using? Is it linux?
Can you post the result of 'ifconfig' command?
In general for RoCEv2 you may not use the rdmacm to establish connection, but still the handshake is going to go through your rdma interface, just not using rdma.