anchor.diff:  
       ?P("[client 2] try connect-init"),
       ServerSockAddr = SockAddr#{port => ServerPort},
  -    ok = gen_sctp:connect_init(CSock2, ServerSockAddr, []),
  +    case gen_sctp:connect_init(CSock2, ServerSockAddr, []) of
  +        ok ->
  +            ok;
  +        {error, Reason2} ->
  +            ?P("<ERROR> failed client 2 connect: "
  +               "~n      Reason: ~p", [Reason2]),
  +            ct:fail({client_connect_failed, 2, Reason2})
  +    end,
  +
       ?P("[client 2] await connect completion"),
       CAssocID2 =
           receive
  
positive.code: 
      ?P("try connect client socket 1"),
      ServerSockAddr = SockAddr#{port => ServerPort},
      {ok, #sctp_assoc_change{state            = comm_up,
                              error            = 0,
                              outbound_streams = COutStreams1,
                              inbound_streams  = CInStreams1,
                              assoc_id         = CAssocID1}} =
  	gen_sctp:connect(CSock1, ServerSockAddr, []),
      ?P("client 1 connected: "
         "~n      Out Streams: ~p"
         "~n      In Streams:  ~p"
  
negative.code:                         end,
                      Filter =
                          fun(#{addr := #{family := D,
                                          addr   := A}} = C) ->
                                  if
                                      (D =:= Domain) andalso
                                      (A =:= LinkLocalAddr) ->
                                          ?P("found link-local candidate: "
                                             "~n   ~p", [C]),
                                          true;
                                      true ->
                                          false
                                  end;                                        
                             (_) ->
                                  false
                          end,
                      case net:getifaddrs(Filter) of
                          {ok, [#{addr := #{scope_id := ScopeID}} = H|T]} ->
                              ?P("found link-local candidate(s): "
                                 "~n   Candidate:         ~p"
                                 "~n   Rest Candidate(s): ~p", [H, T]),
                              SockAddr = #{family   => Domain,
                                           addr     => LinkLocalAddr,
                                           port     => 0,
  