For security purposes, the IP address for the Windows Update web site constantly changes and it is not a fixed address. Also, there is no official publication of the IP addresses. We normally advise against defining IP addresses on the firewall
for this purpose. Instead, we suggest either allowing all outbound connections to http & https ports or defining the DNS addresses as permitted destinations for traffic via the firewall.
For up-to-date information about the IP's being used by Windows Update, use the DNS system, as this is the only reliable up to date source of information. If you use DNS, make sure the following destination hosts are specified: