The Microsoft implementation of the RADIUS standard. RADIUS is used to provide network authentication for users attempting to connect to a network. RADIUS has traditionally been used for dial-up connections, but it has recently begun to see usage in a variety of connection scenarios including wireless network clients.
ICMP (Internet Control Message Protocol)
A protocol in the TCP/IP suite of protocols that is used for testing connectivity. ICMP supports packets that contain error, control, and informational messages and is used by applications such as ping and tracert.
IGMP (Internet Group Management Protocol)
One of the core protocols in the TCP/IP suite, a routing protocol that is used as part of multicasting.
IGP (Interior Gateway Protocol)
A protocol that is used to pass routing information for routing networks that are under a common network administration.
IKE (Internet Key Exchange)
An encryption scheme that allows disparate VPN servers to share encryption key information and make the IPSec protocol practical in today's environment.
Integrated Services Digital Network (ISDN)
A type of channelized connection (also known as a multiport device). A Primary Rate Interface (PRI) ISDN connection can support two data channels, known as B-channels (short for bearer channels). Each of these B-channels can act as the port for a point-to-point connection. There is an additional 16KB D-channel (short for delta channel) that is used for session control and error handling.
intelligent forwarding
See conditional forwarding.
IP (Internet Protocol)
The portion of the TCP/IP suite that is used to provide packet routing.
IP address
The 32-bit binary address that is used to identify a TCP/IP host's network and host ID. IPv6 IP addresses are 128 bits in length.
ipconfig (Internet Protocol Configuration)
A command-line utility that can be used to view the configuration details for the host's TCP/IP properties on all installed network adapters. ipconfig can also be used to release or renew an address leased from a DHCP server as well as to display and flush the local DNS cache.
IPSec (IP Security)
A Layer 3 TCP/IP that provides end-to-end security for data in transit.
ISAKMP/Oakley (Internet Security Association and Key Management Protocol/Oakley)
A protocol that is used to share a public key between sender and receiver of a secure connection. ISAKMP/Oakley allows the receiving system to retrieve a public key and then authenticate the sender by using digital certificates.
iterative query
A DNS query sent from a DNS server to one or more DNS servers in search of the DNS server that is authoritative for the name being sought.
