[angular] Error: Cannot match any routes. URL Segment: - Angular 2

I am new to angular2. I am trying to understand how to use multiple <router-outlets> in a particular template. I have gone though many QA here but couldn't resolve my error.

router.module.ts

const routes: Routes = [
{
    path: '',
    redirectTo: 'one',
    pathMatch: 'full'
},
{
    path: 'two',
    component: ClassTwo, children: [
        {
            path: 'three',
            component: ClassThree,
            outlet: 'nameThree',
        },
        {
            path: 'four',
            component: ClassFour,
            outlet: 'nameFour'
        }
    ]
},];

component1.html

<h3>In One</h3>

<nav>
    <a routerLink="/two" class="dash-item">...Go to Two...</a>
    <a routerLink="/three" class="dash-item">... Go to THREE...</a>
    <a routerLink="/four" class="dash-item">...Go to FOUR...</a>
</nav>

<router-outlet></router-outlet>                   // Successfully loaded component2.html
<router-outlet name="nameThree" ></router-outlet> // Error: Cannot match any routes. URL Segment: 'three'
<router-outlet name="nameFour" ></router-outlet>  // Error: Cannot match any routes. URL Segment: 'three'

component2.html

<h3>In two</h3>

component3.html

<h3>In three</h3>

component4.html

<h3>In four</h3>

The below screenshot is my current output:

When I click ...Go to Two... In two is printed. But clicking on other two links gives me the error Cannot match any routes

please modify your router.module.ts as:

const routes: Routes = [
{
    path: '',
    redirectTo: 'one',
    pathMatch: 'full'
},
{
    path: 'two',
    component: ClassTwo, children: [
        {
            path: 'three',
            component: ClassThree,
            outlet: 'nameThree',
        },
        {
            path: 'four',
            component: ClassFour,
            outlet: 'nameFour'
        },
        {
           path: '',
           redirectTo: 'two',
           pathMatch: 'full'
        }
    ]
},];

and in your component1.html

<h3>In One</h3>

<nav>
    <a routerLink="/two" class="dash-item">...Go to Two...</a>
    <a routerLink="/two/three" class="dash-item">... Go to THREE...</a>
    <a routerLink="/two/four" class="dash-item">...Go to FOUR...</a>
</nav>

<router-outlet></router-outlet>                   // Successfully loaded component2.html
<router-outlet name="nameThree" ></router-outlet> // Error: Cannot match any routes. URL Segment: 'three'
<router-outlet name="nameFour" ></router-outlet>  // Error: Cannot match any routes. URL Segment: 'three'