Hello, FR 3.0.19 Quick one - I have some Aruba APs that are sending the BSSID in the Called-Station-Id attribute instead of the base radio MAC. I need to get back to the base radio MAC, so Aerohive has provided a mask we can apply to find out the base radio MAC from this BSSID. I am doing: if (&Called-Station-Id =~ /^([0-9a-f]{2})[^0-9a-f]?([0-9a-f]{2})[^0-9a-f]?([0-9a-f]{2})[^0-9a-f]?([0-9a-f]{2})[^0-9a-f]?([0-9a-f]{2})[^0-9a-f]?([0-9a-f]{2})([^0-9a-f](.+))?$/i) { update control { &Tmp-String-1 := "%{expr: 0x%{1}%{2}%{3}%{4}%{5}%{6} & 0xFFFFFFFFFFC0}" } } This works and the debug output shows &Tmp-String-1: EXPAND %{expr: 0x%{1}%{2}%{3}%{4}%{5}%{6} & 0xFFFFFFFFFFC0} --> 149928134221440 149928134221440 is correct so I need to base convert this integer back to a real MAC in a format like 88-5B-DD-2E-9E-80 or 885BDD2E9E80 instead of 149928134221440. Any thoughts? Thanks, James