Trouble getting updates - Urls pointing to addresses outside the 17.0.0.0/8 address block

Hi all, our current infrastructure is behind a firewall and we have whitelisted the 17.0.0.0/8 address block. We're getting issues with swdist.apple.com (184.51.48.89), swscan.apple.com (184.51.48.59) and xp.apple.com (184.27.28.73) which are pointing to addresses outside the 17.0.0.0/8 address block. How can we change this? That doesn't look normal and whitelisting those addresses may be out of question for us.