rfc1978 help

Hi all Sth I want to clarify: 1/ 240.0.0.0/5 - Class E Reserved 248.0.0.0/5 - Unallocated Sometimes I got it should /4 or /5 ? 240.0.0.0/4 - Class E Reserved 248.0.0.0/4 - Unallocated 2/ Can I block it in the firewall for "255.255.255.255/32 - Broadcast"? deny ip from any to 255.255.255.255/32 deny ip from 255.255.255.255/32 to any 3/ I got the following. ls it normail? why there is connection to the broadcast address tcp 0 1 202.64.230.8:33397 192.168.255.255:25 SYN_SENT Deny TCP 202.64.230.8:33021 10.254.254.254:25 Deny TCP 202.64.230.8:57798 172.21.143.58:25 Thank you so much