Problem

No such host is known.

HRESULT error: 0x80072AF9
Winsock error: WSAHOST_NOT_FOUND (11001)

HRESULT error: 0x80072ee7
WinHTTP error: ERROR_WINHTTP_NAME_NOT_RESOLVED (12007)

Cause

This error means that the hostname you are trying to connect to cannot be resolved to an IP address. Host names are resolved to IP addresses by a DNS server (Domain Name Server).

Solution

Double check the host name you have entered. 

If you have verified that the hostname is correct, there may be a problem with your DNS server (or with your ISP's DNS server if you are a standalone user). It may be unable to resolve hostnames to IP addresses. At this point it would be a good idea to contact your ISP about the problem, or network administrator.