A first device generates a first knowledge digest encoding first configuration information that is associated with communications to a second device. The first device receives from the second device messages including second knowledge digests encoding second configuration information. The first device compares the first knowledge digest to the second knowledge digest and produces an indication if the second configuration information encoded in the second knowledge digest is not a subset of the first configuration information encoded in the first knowledge digest. The first device indicates the availability of communications between the first device and the second device as long as second knowledge digests continue to be received from the second device and no indication occurs.