Check validity of socket bindings when creating a protocol/protocol stack

JGroups subsystem. When creating a protocol stack, I'm asked to enter a socket-binding (for the transport protocol). The validity of the socket binding isn't verified until I add all the protocols in the protocol stack and then click "Done". Since adding the whole protocol stack is an expensive operation I propose either of these two solutions:

1, For each protocol (including transports) let the user select from a list of available socket bindings (if necessary for given protocol) or let create a new socket binding.

2, Check the validity of socket binding right when it is entered and notify the user of what socket bindings are available, should the entered value be wrong.