How to Redirect to a certain route based on condition in Angular 2.

Here is the better solution: Guard the admin feature according to Angular guide.
Using CanActivate hook
Steps:

1) Add auth-guard.service.ts file

import { Injectable }     from '@angular/core';
import { CanActivate }    from '@angular/router';
import { Router } from '@angular/router';

@Injectable()
export class AuthGuard implements CanActivate {
    canActivate() {
        //Your redirect logic/condition. I use this.

        if (this.user && this.user.profile.role == 'Guest') {
         this.router.navigate(['dashboard']);
        }
        console.log('AuthGuard#canActivate called');
        return true;
    }
    //Constructor 
    constructor(private router: Router) { }
}

2) Update the routing file, in my case it’s app.module.ts

import { AuthGuard } from './auth-guard.service';
import { AdminComponent } from './admin/admin.component';
@NgModule({
  declarations: [
    AppComponent,
    AdminComponent
  ],
  imports: [
    BrowserModule,
    FormsModule,
    HttpModule,

    RouterModule.forRoot([
        {
          path: 'admin',
          component: AdminComponent,
          canActivate:[AuthGuard]
        },
        {
        path: '',
        redirectTo: '/dashboard',
        pathMatch: 'full'
       }
    ])
  ],
  providers: [AuthGuard],
  bootstrap: [AppComponent]
})
export class AppModule { }

**Reference **
https://angular.io/docs/ts/latest/guide/router.html#!#can-activate-guard