network/networkInterface definitions fail to resolve

I've tried three resolvers on [this url](https://raw.githubusercontent.com/Azure/azure-rest-api-specs/current/specification/network/resource-manager/Microsoft.Network/2017-10-01/networkInterface.json) and they all fail to fully resolve the definition:

I believe it affects the following versions of `Microsoft.Network/*/networkInterface.json`

* 2017-06-01
* 2017-08-01
* 2017-09-01
* 2017-10-01

An example error message is:

```
#/components/schemas/NetworkInterfaceIPConfigurationPropertiesFormat/properties/subnet/%24ref
Cannot resolve reference: #/components/schemas/NetworkInterfaceIPConfigurationPropertiesFormat/properties/applicationGatewayBackendAddressPools/items/properties/properties/properties/backendIPConfigurations/items/properties/properties/properties/subnet/properties/properties/properties/routeTable/properties/properties/properties/subnets/items
```

And a `$ref` which is left unresolved is

```
./applicationGateway.json#/definitions/ApplicationGatewayBackendAddressPool
```

Compare the listed Microsoft.Network networkInterface.json versions and follow the unresolved ./applicationGateway.json#/definitions/ApplicationGatewayBackendAddressPool reference. Start by checking how these external definitions are linked and reproduce the failure with an available resolver. Done means the affected references resolve fully in all four versions.

Written by the indexing model from the issue text.