Steam Client Update Blocked by Sky Broadband Sheild

[eric19371]

Hello all. I have just installed the Steam client on a laptop after about a year away from the platform and I have discovered that the update process is blocked by my ISP's parental control software (Sky Broadband Shield) and gives an error "Steam needs to be online to update". If I disable Broadband Sheild it updates fine. Does anybody know what servers need to be added to the exclusion list so I can continue to use Steam but block the nasty stuff.