Test Ryu-OpenFlow:

        local src=$1 dst=$2 pattern=$3

        local output

        output=$(curl -s "http://172.254.252.11:5000/ping?source=${src}&target=${dst}&count=3")

        echo "$output"

        echo "$output" | grep -E "$pattern"

        if echo "$output" | grep -E "$pattern" >/dev/null; then

          echo "PASSED ${src}->${dst}

        else

          echo "FAILED ${src}->${dst}

          return 1

        fi

      }

    # Run end-to-end test: test no connectivity with ping