hardware handshake. Method of flow control using two con- trol lines, usually Request to Send (RTS) and Clear to Send (CTS).
header. The portion of a packet, preceding the actual data, containing source and destination addresses and
HMAC.
hop. A unit for measuring the number of routers a packet has passed through when traveling from one network to another.
hop count. Distance, measured in the number of routers to be traversed, from a local router to a remote network. See metric.
hub. Another name for a repeater. The hub is a critical network element that connects everything to one centralized point. A hub is simply a box with multiple ports for network connections. Each device on the network is attached to the hub via an Ether- net cable.
IKE. Internet Key Exchange protocol provides automated key management and is a preferred alternative to manual key man- agement as it provides better security. Manual key manage- ment is practical in a small, static environment of two or three sites. Exchanging the key is done through manual means. Because IKE provides automated key exchange, it is good for larger, more dynamic environments.
INSPECTION. The best option for Internet communications security is to have an SMLI firewall constantly inspecting the flow of traffic: determining direction, limiting or eliminating
