Hi,

NavLink component uses "react-router-dom", so you have to set up Routing in your app.

You can do it globally or locally inside component (depends on your needs and your app structure).

f.e.

import React from "react";
import { Navbar, NavbarBrand, NavbarNav, NavItem, NavLink, NavbarToggler, Collapse, FormInline, Dropdown, DropdownToggle, DropdownMenu, DropdownItem, Fa } from "mdbreact";


import { BrowserRouter as Router } from "react-router-dom";


class NavbarPage extends React.Component {
  state = {
    isOpen: false
  };

  toggleCollapse = this.setState({ isOpen: !this.state.isOpen });

  render() {
    return (
      <Router>
        <Navbar color="default-color" dark expand="md" style={{marginTop: "20px"}}>
          <NavbarBrand>
            <strong className="white-text">Navbar</strong>
          </NavbarBrand>
          <NavbarToggler
            onClick={this.toggleCollapse}
          />
          <Collapse id="navbarCollapse3" isOpen={this.state.isOpen} navbar>
          <NavbarNav left>
          <NavItem active>
            <NavLink to="#!">Home</NavLink>
          </NavItem>
          <NavItem>
            <NavLink to="#!">Features</NavLink>
          </NavItem>
          <NavItem>
            <NavLink to="#!">Pricing</NavLink>
          </NavItem>
          <NavItem>
            <Dropdown>
              <DropdownToggle nav caret>
                <div className="d-none d-md-inline">Dropdown</div>
              </DropdownToggle>
              <DropdownMenu className="dropdown-default"right>
                <DropdownItem href="#!">Action</DropdownItem>
                <DropdownItem href="#!">Another Action</DropdownItem>
                <DropdownItem href="#!">Something else here</DropdownItem>
                <DropdownItem href="#!">Something else here</DropdownItem>
              </DropdownMenu>
            </Dropdown>
          </NavItem>
        </NavbarNav>
        <NavbarNav right>
          <NavItem>
            <NavLink className="waves-effect waves-light" to="#!"><Fa icon="twitter" /></NavLink>
          </NavItem>
          <NavItem>
            <NavLink className="waves-effect waves-light" to="#!"><Fa icon="google-plus" /></NavLink>
          </NavItem>
          <NavItem>
            <Dropdown>
              <DropdownToggle nav caret>
                <Fa icon="user" />
              </DropdownToggle>
              <DropdownMenu className="dropdown-default" right>
                <DropdownItem href="#!">Action</DropdownItem>
                <DropdownItem href="#!">Another Action</DropdownItem>
                <DropdownItem href="#!">Something else here</DropdownItem>
                <DropdownItem href="#!">Something else here</DropdownItem>
              </DropdownMenu>
            </Dropdown>
          </NavItem>
        </NavbarNav>
      </Collapse>
    </Navbar>
  </Router>
  );
}
}

export default NavbarPage;