anchor.diff:  * <a href="#config-dns-lb">Step 5: Configure DNS and Load Balancers</a></td>
   * <a href="#config-firewall">Step 6: Configure Firewall Rules</a></td>
   * <a href="#gcp-implementation">Additional GCP Information</a></td>
  -* <a href="#sharding-routers-isolation-segment">Sharding Routers for Isolation Segments</a></td>
   * <a href="#isolation-segments-metrics">Metrics for Routers Associated with Isolation</a></td>
   <% end %>
   
  
positive.code: * "Backend Services" in the GCP [documentation](https://cloud.google.com/compute/docs/load-balancing/http/backend-service)
  * BOSH Google Compute Engine CPI GitHub [repo](https://github.com/cloudfoundry-incubator/bosh-google-cpi-release/tree/master/src/bosh-google-cpi)
  
  ## <a name='sharding-routers-isolation-segment'></a> Sharding Routers for Isolation Segments
  
  To provide security guarantees in addition to the firewall rules described above, an operator can configure sharding of Gorouter's routing table, resulting in a router dedicated for an isolation segment having knowledge only of routes for applications in the same isolation segment. The flexibility of the configuration also supports deployment of a router that is responsible for multiple isolation segments, or that excludes all isolation segments.
  
negative.code: The `router_shared` router will register all routes that do not have an `isolation_segment` value.
  The `router_is1` router will only register routes that have an `isolation_segment` value of `is1`.
  
  <% else %>
  <% end %>
  
  ##<a name='isolation-segments-metrics'></a>Metrics for Routers Associated with Isolation Segments
  
  For metrics emitted by the Gorouter, metrics can be distinguished by the name of the job.
  