1) in ip v4, does the router need to update the ip header checksum hop by hop? why? 2) is aloha good for heavy traffic or light traffic? 3) i took my laptop to willard building, and connected to the penn state wireless lan. what protocol did i use to get my ip address for this connection? 4) in ipv4, how many bits are used to represent the source ip address? what protocol is used to get the mac address of a node based on its ip address?