如何从主机应用程序访问虚拟机中IIS上托管的asp.net Web服务？

I have some webservices hosted in a sharepoint environment on a virtual machine. These services are accessible from within the VM, but when I try to invoke this service from my asp.net application on the host machine I get an error with status 500 and a soap fault exception (unauthorized access). The IIS setting on both host and VM allows anonymous access. I have some webservices hosted in a sharepoint