It is accessible via standard ports such as 80 and 443 - make sure you have those exceptions defined in your firewall settings.
If you are referencing a DNS names outside the firewall other than the default computer name - you will have to add that DNS name to the host white list in the virtual proxy settings:
Host white list All values added here are validated starting from the bottom level. If, for example, domain.com is added, this means that all values ending with domain.com will be approved. If subdomain.domain.com is added, this means that all values ending with subdomain.domain.com will be approved.
Let us know how you do.
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