<glossary id="glossary-1"><title>Glossary</title><para>This glossary contains definitions of new terms in this book that are
not in the <citetitle>Sun Global Glossary</citetitle> available from the <literal>docs.sun.com</literal> web site.</para><glossentry id="glossary-120"><glossterm>3DES</glossterm><glossdef><para>See <olink targetptr="glossary-31" remap="internal">Triple-DES</olink>.</para>
</glossdef>
</glossentry><glossentry id="glossary-73"><glossterm>address pool</glossterm><glossdef><para>In Mobile IP, a set of addresses that are designated by the
home network administrator for use by mobile nodes that need a home address.</para>
</glossdef>
</glossentry><glossentry id="glossary-36"><glossterm>AES</glossterm><glossdef><para>Advanced Encryption Standard. A symmetric 128-bit block data
encryption technique. The U.S. government adopted the Rijndael variant of
the algorithm as its encryption standard in October 2000. AES replaces <olink targetptr="glossary-37" remap="internal">DES</olink> encryption as the government standard.</para>
</glossdef>
</glossentry><glossentry id="glossary-74"><glossterm>agent advertisement</glossterm><glossdef><para>In Mobile IP, a message that is periodically sent by home
agents and foreign agents to advertise their presence on any attached link.</para>
</glossdef>
</glossentry><glossentry id="glossary-75"><glossterm>agent discovery</glossterm><glossdef><para>In Mobile IP, the process by which a mobile node determines
if it has moved, its current location, and its care-of address on a foreign
network.</para>
</glossdef>
</glossentry><glossentry id="glossary-10"><glossterm>anycast address</glossterm><glossdef><para>An IPv6 address that is assigned to a group of interfaces
(typically belonging to different nodes). A packet that is sent to an anycast
address is routed to the <emphasis>nearest</emphasis> interface having that
address. The packet's route is in compliance with the routing protocol's measure
of distance.</para>
</glossdef>
</glossentry><glossentry><glossterm>anycast group</glossterm><glossdef><para>A group of interfaces with the same anycast IPv6 address.
The Solaris OS implementation of IPv6 does not support the creation of anycast
addresses and groups. However, Solaris IPv6 nodes can send traffic to anycast
groups.</para>
</glossdef>
</glossentry><glossentry id="glossary-47"><glossterm>asymmetric key cryptography</glossterm><glossdef><para>An encryption system in which the sender and receiver of a
message use different keys to encrypt and decrypt the message. Asymmetric
keys are used to establish a secure channel for symmetric key encryption.
The <olink targetptr="glossary-54" remap="internal">Diffie-Hellman protocol</olink> is an example
of an asymmetric key protocol. Contrast with <olink targetptr="glossary-40" remap="internal">symmetric
key cryptography</olink>.</para>
</glossdef>
</glossentry><glossentry id="glossary-34"><glossterm>authentication header</glossterm><glossdef><para>An extension header that provides authentication and integrity,
without confidentiality, to IP datagrams.</para>
</glossdef>
</glossentry><glossentry id="glossary-21"><glossterm>autoconfiguration</glossterm><glossdef><para>The process where a host automatically configures its IPv6
address from the site prefix and the local MAC address.</para>
</glossdef>
</glossentry><glossentry id="glossary-76"><glossterm>bidirectional tunnel</glossterm><glossdef><para>A tunnel that can transmit datagrams in both directions.</para>
</glossdef>
</glossentry><glossentry id="glossary-77"><glossterm>binding table</glossterm><glossdef><para>In Mobile IP, a home agent table that associates a home address
with a care-of address, including remaining lifetime and time granted.</para>
</glossdef>
</glossentry><glossentry id="glossary-33"><glossterm>Blowfish</glossterm><glossdef><para>A symmetric block cipher algorithm that takes a variable-length
key from 32 bits to 448 bits. Its author, Bruce Schneier, claims that Blowfish
is optimized for applications where the key does not change often.</para>
</glossdef>
</glossentry><glossentry id="glossary-145"><glossterm>broadcast address</glossterm><glossdef><para>IPv4 network addresses with the host portion of the address
having all zeroes (10.50.0.0) or all one bits (10.50.255.255). A packet that
is sent to a broadcast address from a machine on the local network is delivered
to all machines on that network.</para>
</glossdef>
</glossentry><glossentry id="glossary-131"><glossterm>CA</glossterm><glossdef><para>See <olink targetptr="glossary-41" remap="internal">certificate authority (CA)</olink>.</para>
</glossdef>
</glossentry><glossentry id="glossary-78"><glossterm>care-of address</glossterm><glossdef><para>A mobile node's temporary address that is used as a tunnel
exit point when the mobile node is connected to a foreign network.</para>
</glossdef>
</glossentry><glossentry id="glossary-41"><glossterm>certificate authority (CA)</glossterm><glossdef><para>A trusted third-party organization or company that issues
digital certificates used to create digital signatures and public-private
key pairs. The CA guarantees the identity of the individual who is granted
the unique certificate.</para>
</glossdef>
</glossentry><glossentry id="glossary-123"><glossterm>certificate revocation list (CRL)</glossterm><glossdef><para>A list of public key certificates that have been revoked by
a CA. CRLs are stored in the CRL database that is maintained through IKE.</para>
</glossdef>
</glossentry><glossentry><glossterm>classless inter-domain routing (CIDR) address</glossterm><glossdef><para>An IPv4 address format that is not based on network classes
(Class A, B, and C). CIDR addresses are 32 bits in length. They use the standard
IPv4 dotted decimal notation format, with the addition of a network prefix.
This prefix defines the network number and the network mask.</para>
</glossdef>
</glossentry><glossentry id="glossary-101"><glossterm>class</glossterm><glossdef><para>In IPQoS, a group of network flows that share similar characteristics.
You define classes in the IPQoS configuration file.</para>
</glossdef>
</glossentry><glossentry id="glossary-133"><glossterm>datagram</glossterm><glossdef><para>See <olink targetptr="glossary-121" remap="internal">IP datagram</olink>.</para>
</glossdef>
</glossentry><glossentry id="glossary-37"><glossterm>DES</glossterm><glossdef><para>Data Encryption Standard. A symmetric-key encryption method
developed in 1975 and standardized by ANSI in 1981 as ANSI X.3.92. DES uses
a 56-bit key.</para>
</glossdef>
</glossentry><glossentry id="glossary-102"><glossterm>diffserv model</glossterm><glossdef><para>Internet Engineering Task Force architectural standard for
implementing differentiated services on IP networks. The major modules are
classifier, meter, marker, scheduler, and dropper. IPQoS implements the classifier,
meter, and marker modules. The diffserv model is described in RFC 2475, <emphasis>An Architecture for Differentiated Services</emphasis>.</para>
</glossdef>
</glossentry><glossentry id="glossary-39"><glossterm>digital signature</glossterm><glossdef><para>A digital code that is attached to an electronically transmitted
message that uniquely identifies the sender.</para>
</glossdef>
</glossentry><glossentry id="glossary-125"><glossterm>domain of interpretation (DOI)</glossterm><glossdef><para>A DOI defines data formats, network traffic exchange types,
and conventions for naming security-relevant information. Security policies,
cryptographic algorithms, and cryptographic modes are examples of security-relevant
information.</para>
</glossdef>
</glossentry><glossentry id="glossary-45"><glossterm>DSA</glossterm><glossdef><para>Digital Signature Algorithm. A public key algorithm with a
variable key size from 512 to 4096 bits. The U.S. Government standard, DSS,
goes up to 1024 bits. DSA relies on <olink targetptr="glossary-62" remap="internal">SHA-1</olink> for
input.</para>
</glossdef>
</glossentry><glossentry id="glossary-103"><glossterm>DS codepoint (DSCP)</glossterm><glossdef><para>A 6-bit value that, when included in the DS field of an IP
header, indicates how a packet must be forwarded.</para>
</glossdef>
</glossentry><glossentry id="glossary-54"><glossterm>Diffie-Hellman protocol</glossterm><glossdef><para>Also known as public key cryptography. An asymmetric cryptographic
key agreement protocol that was developed by Diffie and Hellman in 1976. The
protocol enables two users to exchange a secret key over an insecure medium
without any prior secrets. Diffie-Hellman is used by the IKE protocol.</para>
</glossdef>
</glossentry><glossentry id="glossary-44"><glossterm>dual stack</glossterm><glossdef><para>A TCP/IP protocol stack with both IPv4 and IPv6 at the network
layer, with the rest of the stack being identical. When you enable IPv6 during
Solaris OS installation, the host receives the dual-stack version of TCP/IP.</para>
</glossdef>
</glossentry><glossentry id="glossary-146"><glossterm>dynamic packet filter</glossterm><glossdef><para>See <olink targetptr="glossary-152" remap="internal">stateful packet filter</olink>.</para>
</glossdef>
</glossentry><glossentry id="glossary-35"><glossterm>encapsulating security payload (ESP)</glossterm><glossdef><para>An extension header that provides integrity and confidentiality
to datagrams. ESP is one of the five components of the IP Security Architecture
(IPsec).</para>
</glossdef>
</glossentry><glossentry id="glossary-55"><glossterm>encapsulation</glossterm><glossdef><para>The process of a header and payload being placed in the first
packet, which is subsequently placed in the second packet's payload.</para>
</glossdef>
</glossentry><glossentry id="glossary-63"><glossterm>failback</glossterm><glossdef><para>The process of switching back network access to an interface
that has its repair detected.</para>
</glossdef>
</glossentry><glossentry id="glossary-64"><glossterm>failover</glossterm><glossdef><para>The process of switching network access from a failed interface
to a good physical interface. Network access includes IPv4 unicast, multicast,
and broadcast traffic, as well as IPv6 unicast and multicast traffic.</para>
</glossdef>
</glossentry><glossentry id="glossary-65"><glossterm>failure detection</glossterm><glossdef><para>The process of detecting when an interface or the path from
an interface to an Internet layer device no longer works. IP network multipathing
(IPMP) includes two types of failure detection: link based (default) and probe
based (optional).</para>
</glossdef>
</glossentry><glossentry id="glossary-104"><glossterm>filter</glossterm><glossdef><para>A set of rules that define the characteristics of a class
in the IPQoS configuration file. The IPQoS system selects for processing any
traffic flows that conform to the filters in its IPQoS configuration file.
See <olink targetptr="glossary-142" remap="internal">packet filter</olink>.</para>
</glossdef>
</glossentry><glossentry id="glossary-46"><glossterm>firewall</glossterm><glossdef><para>Any device or software that isolates an organization's private
network or intranet from the Internet, thus protecting it from external intrusions.
A firewall can include packet filtering, proxy servers, and NAT (network address
translation).</para>
</glossdef>
</glossentry><glossentry id="glossary-105"><glossterm>flow accounting</glossterm><glossdef><para>In IPQoS, the process of accumulating and recording information
about traffic flows. You establish flow accounting by defining parameters
for the <command>flowacct</command> module in the IPQoS configuration file.</para>
</glossdef>
</glossentry><glossentry id="glossary-99"><glossterm>foreign agent</glossterm><glossdef><para>A router or server on the foreign network that the mobile
node visits.</para>
</glossdef>
</glossentry><glossentry id="glossary-79"><glossterm>foreign network</glossterm><glossdef><para>Any network other than the mobile node's home network.</para>
</glossdef>
</glossentry><glossentry id="glossary-100"><glossterm>forward tunnel</glossterm><glossdef><para>A tunnel that starts at the home agent and terminates at the
mobile node's care-of address.</para>
</glossdef>
</glossentry><glossentry id="glossary-80"><glossterm>Generic Routing Encapsulation (GRE)</glossterm><glossdef><para>An optional form of tunneling that can be supported by home
agents, foreign agents, and mobile nodes. GRE enables a packet of any network-layer
protocol to be encapsulated within a delivery packet of any other (or the
same) network-layer protocol.</para>
</glossdef>
</glossentry><glossentry id="glossary-42"><glossterm>hash value</glossterm><glossdef><para>A number that is generated from a string of text. Hash functions
are used to ensure that transmitted messages have not been tampered with. <olink targetptr="glossary-84" remap="internal">MD5</olink> and <olink targetptr="glossary-62" remap="internal">SHA-1</olink> are
examples of one-way hash functions.</para>
</glossdef>
</glossentry><glossentry id="glossary-134"><glossterm>header</glossterm><glossdef><para>See <olink targetptr="glossary-137" remap="internal">IP header</olink>.</para>
</glossdef>
</glossentry><glossentry id="glossary-32"><glossterm>HMAC</glossterm><glossdef><para>Keyed hashing method for message authentication. HMAC is a
secret key authentication algorithm. HMAC is used with an iterative cryptographic
hash function, such as MD5 or SHA-1, in combination with a secret shared key.
The cryptographic strength of HMAC depends on the properties of the underlying
hash function.</para>
</glossdef>
</glossentry><glossentry id="glossary-81"><glossterm>home address</glossterm><glossdef><para>An IP address that is assigned for an extended period to a
mobile node. The address remains unchanged when the node is attached elsewhere
on the Internet or an organization's network.</para>
</glossdef>
</glossentry><glossentry id="glossary-98"><glossterm>home agent</glossterm><glossdef><para>A router or server on the home network of a mobile node.</para>
</glossdef>
</glossentry><glossentry id="glossary-82"><glossterm>home network</glossterm><glossdef><para>A network that has a network prefix that matches the network
prefix of a mobile node's home address. </para>
</glossdef>
</glossentry><glossentry id="glossary-61"><glossterm>hop</glossterm><glossdef><para>A measure that is used to identify the number of routers that
separate two hosts. If three routers separate a source and destination, the
hosts are four hops away from each other.</para>
</glossdef>
</glossentry><glossentry><glossterm>host</glossterm><glossdef><para>A system that does not perform packet forwarding. Upon installation
of the Solaris OS, a system becomes a host by default, that is, the system
cannot forward packets. A host typically has one physical interface, although
it can have multiple interfaces.</para>
</glossdef>
</glossentry><glossentry id="glossary-147"><glossterm>ICMP</glossterm><glossdef><para>Internet Control Message Protocol. Used to handle errors and
exchange control messages.</para>
</glossdef>
</glossentry><glossentry id="glossary-148"><glossterm>ICMP echo request packet</glossterm><glossdef><para>A packet sent to a machine on the Internet to solicit a response.
Such packets are commonly known as &ldquo;ping&rdquo; packets.</para>
</glossdef>
</glossentry><glossentry id="glossary-56"><glossterm>IKE</glossterm><glossdef><para>Internet Key Exchange. IKE automates the provision of authenticated
keying material for IPsec <olink targetptr="glossary-51" remap="internal">security association
(SA)</olink>s.</para>
</glossdef>
</glossentry><glossentry id="glossary-135"><glossterm>Internet Protocol (IP)</glossterm><glossdef><para>The method or protocol by which data is sent from one computer
to another on the Internet.</para>
</glossdef>
</glossentry><glossentry id="glossary-136"><glossterm>IP</glossterm><glossdef><para>See <olink targetptr="glossary-135" remap="internal">Internet Protocol (IP)</olink>, <olink targetptr="glossary-24" remap="internal">IPv4</olink>, <olink targetptr="glossary-25" remap="internal">IPv6</olink>.</para>
</glossdef>
</glossentry><glossentry id="glossary-121"><glossterm>IP datagram</glossterm><glossdef><para>A packet of information that is carried over IP. An IP datagram
contains a header and data. The header includes the addresses of the source
and the destination of the datagram. Other fields in the header help identify
and recombine the data with accompanying datagrams at the destination.</para>
</glossdef>
</glossentry><glossentry id="glossary-137"><glossterm>IP header</glossterm><glossdef><para>Twenty bytes of data that uniquely identify an Internet packet.
The header includes source and destination addresses for the packet. An option
exists within the header to allow further bytes to be added.</para>
</glossdef>
</glossentry><glossentry id="glossary-83"><glossterm>IP in IP encapsulation</glossterm><glossdef><para>The mechanism for tunneling IP packets within IP packets.</para>
</glossdef>
</glossentry><glossentry id="glossary-66"><glossterm>IP link</glossterm><glossdef><para>A communication facility or medium over which nodes can communicate
at the link layer. The link layer is the layer immediately below IPv4/IPv6.
Examples include Ethernets (simple or bridged) or ATM networks. One or more
IPv4 subnet numbers or prefixes are assigned to an IP link. A subnet number
or prefix cannot be assigned to more than one IP link. In ATM LANE, an IP
link is a single emulated LAN. When you use ARP, the scope of the ARP protocol
is a single IP link.</para>
</glossdef>
</glossentry><glossentry id="glossary-106"><glossterm>IPQoS</glossterm><glossdef><para>A software feature that provides an implementation of the <olink targetptr="glossary-102" remap="internal">diffserv model</olink> standard, plus flow accounting
and 802.1 D marking for virtual LANs. Using IPQoS, you can provide different
levels of network services to customers and applications, as defined in the
IPQoS configuration file.</para>
</glossdef>
</glossentry><glossentry id="glossary-28"><glossterm>IPsec</glossterm><glossdef><para>IP security. The security architecture that provides protection
for IP datagrams.</para>
</glossdef>
</glossentry><glossentry id="glossary-138"><glossterm>IP stack</glossterm><glossdef><para>TCP/IP is frequently referred to as a &ldquo;stack.&rdquo;
This refers to the  layers (TCP, IP, and sometimes others) through which all
data passes at both client and server ends of a data exchange. </para>
</glossdef>
</glossentry><glossentry id="glossary-24"><glossterm>IPv4</glossterm><glossdef><para>Internet Protocol, version 4. IPv4 is sometimes referred to
as IP. This version supports a 32-bit address space.</para>
</glossdef>
</glossentry><glossentry id="glossary-25"><glossterm>IPv6</glossterm><glossdef><para>Internet Protocol, version 6. IPv6 supports a 128-bit address
space.</para>
</glossdef>
</glossentry><glossentry id="glossary-53"><glossterm>key management</glossterm><glossdef><para>The way in which you manage <olink targetptr="glossary-51" remap="internal">security
association (SA)</olink>s.</para>
</glossdef>
</glossentry><glossentry id="glossary-124"><glossterm>keystore name</glossterm><glossdef><para>The name that an administrator gives to the storage area,
or keystore, on a <olink targetptr="glossary-67" remap="internal">network interface card (NIC)</olink>.
The keystore name is also called the token or the token ID.</para>
</glossdef>
</glossentry><glossentry id="glossary-13"><glossterm>link-local address</glossterm><glossdef><para>In IPv6, a designation that is used for addressing on a single
link for purposes such as automatic address configuration. By default, the
link-local address is created from the system's MAC address.</para>
</glossdef>
</glossentry><glossentry id="glossary-12"><glossterm>local-use address</glossterm><glossdef><para>A unicast address that has only local routability scope (within
the subnet or within a subscriber network). This address also can have a local
or global uniqueness scope.</para>
</glossdef>
</glossentry><glossentry id="glossary-139"><glossterm>link layer</glossterm><glossdef><para>The layer immediately below <olink targetptr="glossary-24" remap="internal">IPv4</olink>/<olink targetptr="glossary-25" remap="internal">IPv6</olink>.</para>
</glossdef>
</glossentry><glossentry id="glossary-107"><glossterm>marker</glossterm><glossdef><para>1. A module in the diffserv architecture and IPQoS that marks
the DS field of an IP packet with a value that indicates how the packet is
to be forwarded. In the IPQoS implementation, the marker module is <command>dscpmk</command>.</para><para>2. A module in the IPQoS implementation that marks
the virtual LAN tag of an Ethernet datagram with a user priority value. The
user priority value indicates how datagrams are to be forwarded on a network
with VLAN devices. This module is called <command>dlcosmk</command>. </para>
</glossdef>
</glossentry><glossentry id="glossary-84"><glossterm>MD5</glossterm><glossdef><para>An iterative cryptographic hash function that is used for
message authentication, including digital signatures. The function was developed
in 1991 by Rivest.</para>
</glossdef>
</glossentry><glossentry id="glossary-126"><glossterm>message authentication code (MAC)</glossterm><glossdef><para>MAC provides assurance of data integrity and authenticates
data origin. MAC does not protect against eavesdropping.</para>
</glossdef>
</glossentry><glossentry id="glossary-108"><glossterm>meter</glossterm><glossdef><para>A module in the diffserv architecture that measures the rate
of traffic flow for a particular class. The IPQoS implementation includes
two meters, <command>tokenmt</command> and <command>tswtclmt</command>.</para>
</glossdef>
</glossentry><glossentry id="glossary-85"><glossterm>minimal encapsulation</glossterm><glossdef><para>An optional form of IPv4 in IPv4 tunneling that can be supported
by home agents, foreign agents, and mobile nodes. Minimal encapsulation has
8 or 12 bytes less of overhead than does IP in IP encapsulation.</para>
</glossdef>
</glossentry><glossentry id="glossary-27"><glossterm>mobile node</glossterm><glossdef><para>A host or router that can change its point of attachment from
one network to another network while maintaining all existing communications
by using its IP home address.</para>
</glossdef>
</glossentry><glossentry id="glossary-86"><glossterm>mobility agent</glossterm><glossdef><para>Either a home agent or a foreign agent.</para>
</glossdef>
</glossentry><glossentry id="glossary-87"><glossterm>mobility binding</glossterm><glossdef><para>The association of a home address with a care-of address,
along with the remaining lifetime of that association.</para>
</glossdef>
</glossentry><glossentry id="glossary-88"><glossterm>mobility security association</glossterm><glossdef><para>A collection of security measures, such as an authentication
algorithm, between a pair of nodes, which are applied to Mobile IP protocol
messages that are exchanged between the two nodes. </para>
</glossdef>
</glossentry><glossentry id="glossary-30"><glossterm>MTU</glossterm><glossdef><para>Maximum Transmission Unit. The size, given in octets, that
can be transmitted over a link. For example, the MTU of an Ethernet is 1500
octets.</para>
</glossdef>
</glossentry><glossentry id="glossary-11"><glossterm>multicast address</glossterm><glossdef><para>An IPv6 address that identifies a group of interfaces in a
particular way. A packet that is sent to a multicast address is delivered
to all of the interfaces in the group. The IPv6 multicast address has similar
functionality to the IPv4 broadcast address.</para>
</glossdef>
</glossentry><glossentry><glossterm>multihomed host</glossterm><glossdef><para>A system that has more than one physical interface and that
does not perform packet forwarding. A multihomed host can run routing protocols.</para>
</glossdef>
</glossentry><glossentry id="glossary-140"><glossterm>NAT</glossterm><glossdef><para>See <olink targetptr="glossary-141" remap="internal">network address translation</olink>.</para>
</glossdef>
</glossentry><glossentry id="glossary-18"><glossterm>neighbor advertisement</glossterm><glossdef><para>A response to a neighbor solicitation message or the process
of a node sending unsolicited neighbor advertisements to announce a link-layer
address change.</para>
</glossdef>
</glossentry><glossentry id="glossary-15"><glossterm>neighbor discovery</glossterm><glossdef><para>An IP mechanism that enables hosts to locate other hosts that
reside on an attached link.</para>
</glossdef>
</glossentry><glossentry id="glossary-19"><glossterm>neighbor solicitation</glossterm><glossdef><para>A solicitation that is sent by a node to determine the link-layer
address of a neighbor. A neighbor solicitation also verifies that a neighbor
is still reachable by a cached link-layer address.</para>
</glossdef>
</glossentry><glossentry id="glossary-89"><glossterm>Network Access Identifier (NAI)</glossterm><glossdef><para>A designation that uniquely identifies the mobile node in
the format of user@domain.</para>
</glossdef>
</glossentry><glossentry id="glossary-141"><glossterm>network address translation</glossterm><glossdef><para>NAT. The translation of an IP address used within one network
to a different IP address known within another network. Used to limit the
number of global IP addresses that are needed.</para>
</glossdef>
</glossentry><glossentry id="glossary-67"><glossterm>network interface card (NIC)</glossterm><glossdef><para>Network adapter card that is an interface to a network. Some
NICs can have multiple physical interfaces, such as the <command>qfe</command> card.</para>
</glossdef>
</glossentry><glossentry id="glossary-90"><glossterm>node</glossterm><glossdef><para>In IPv6, any system that is IPv6-enabled, whether a host or
a router.</para>
</glossdef>
</glossentry><glossentry id="glossary-109"><glossterm>outcome</glossterm><glossdef><para>The action to take as a result of metering traffic. The IPQoS
meters have three outcomes, red, yellow, and green, which you define in the
IPQoS configuration file.</para>
</glossdef>
</glossentry><glossentry id="glossary-26"><glossterm>packet</glossterm><glossdef><para>A group of information that is transmitted as a unit over
communications lines. Contains an <olink targetptr="glossary-137" remap="internal">IP header</olink> plus
a <olink targetptr="glossary-122" remap="internal">payload</olink>.</para>
</glossdef>
</glossentry><glossentry id="glossary-142"><glossterm>packet filter</glossterm><glossdef><para>A firewall function that can be configured to allow or disallow
specified packets through a firewall. </para>
</glossdef>
</glossentry><glossentry id="glossary-149"><glossterm>packet header</glossterm><glossdef><para>See <olink targetptr="glossary-137" remap="internal">IP header</olink>.</para>
</glossdef>
</glossentry><glossentry id="glossary-122"><glossterm>payload</glossterm><glossdef><para>The data that is carried in a packet. The payload does not
include the header information that is required to get the packet to its destination.</para>
</glossdef>
</glossentry><glossentry id="glossary-114"><glossterm>perfect forward secrecy (PFS)</glossterm><glossdef><para>In PFS, the key that is used to protect transmission of data
is not used to derive additional keys. Also, the source of the key that is
used to protect data transmission is never used to derive additional keys.</para><para>PFS applies to authenticated key exchange only. See also <olink targetptr="glossary-54" remap="internal">Diffie-Hellman protocol</olink>.</para>
</glossdef>
</glossentry><glossentry id="glossary-110"><glossterm>per-hop behavior (PHB)</glossterm><glossdef><para>A priority that is assigned to a traffic class. The PHB indicates
the precedence which flows of that class have in relation to other traffic
classes.</para>
</glossdef>
</glossentry><glossentry id="glossary-68"><glossterm>physical interface</glossterm><glossdef><para>A system's attachment to a link. This attachment is often
implemented as a device driver plus a network interface card (NIC). Some NICs
can have multiple points of attachment, for example, <literal>qfe</literal>. </para>
</glossdef>
</glossentry><glossentry id="glossary-69"><glossterm>physical interface group</glossterm><glossdef><para>The set of physical interfaces on a system that are connected
to the same link. These interfaces are identified by assigning the same (non-null)
character string name to all the physical interfaces in the group.</para>
</glossdef>
</glossentry><glossentry id="glossary-70"><glossterm>physical interface group name</glossterm><glossdef><para>A name that is assigned to a physical interface that identifies
the group. The name is local to a system. Multiple physical interfaces, sharing
the same group name, form a physical interface group.</para>
</glossdef>
</glossentry><glossentry><glossterm>plumb</glossterm><glossdef><para>The act of opening a device that is associated with a physical
interface name. When an interface is plumbed, streams are set up so that the
IP protocol can use the device. You use the <command>ifconfig</command> command
to plumb an interface during a system's current session.</para>
</glossdef>
</glossentry><glossentry id="glossary-29"><glossterm>PKI</glossterm><glossdef><para>Public Key Infrastructure. A system of digital certificates,
Certificate Authorities, and other registration authorities that verify and
authenticate the validity of each party involved in an Internet transaction.</para>
</glossdef>
</glossentry><glossentry id="glossary-91"><glossterm>private address</glossterm><glossdef><para>An IP address that is not routable through the Internet. Private
addresses can used by internal networks on hosts that do not require Internet
connectivity. These addresses are defined in <ulink url="http://www.ietf.org/rfc/rfc1918.txt?number=1918" type="text_url">Address
Allocation for Private Internets</ulink> and often referred to as &ldquo;1918&rdquo;
addresses.</para>
</glossdef>
</glossentry><glossentry id="glossary-150"><glossterm>protocol stack</glossterm><glossdef><para>See <olink targetptr="glossary-138" remap="internal">IP stack</olink>.</para>
</glossdef>
</glossentry><glossentry id="glossary-153"><glossterm>proxy server</glossterm><glossdef><para>A server that sits between a client application, such as a
Web browser, and another server. Used to filter requests&mdash;to prevent
access to certain web sites, for instance. </para>
</glossdef>
</glossentry><glossentry id="glossary-38"><glossterm>public key cryptography</glossterm><glossdef><para>A cryptographic system that uses two different keys. The public
key is known to everyone. The private key is known only to the recipient of
the message. IKE provides public keys for IPsec.</para>
</glossdef>
</glossentry><glossentry id="glossary-43"><glossterm>redirect</glossterm><glossdef><para>In a router, to inform a host of a better first-hop node to
reach a particular destination.</para>
</glossdef>
</glossentry><glossentry id="glossary-92"><glossterm>registration</glossterm><glossdef><para>The process by which a mobile node registers its care-of address
with its home agent and foreign agent when it is away from home.</para>
</glossdef>
</glossentry><glossentry id="glossary-71"><glossterm>repair detection</glossterm><glossdef><para>The process of detecting when a NIC or the path from the NIC
to some layer-3 device starts operating correctly after a failure.</para>
</glossdef>
</glossentry><glossentry id="glossary-156"><glossterm>replay attack</glossterm><glossdef><para>In IPsec, an attack in which a packet is captured by an intruder.
The stored packet then replaces or repeats the original at a later time. To
protect against such attacks, a packet can contain a field that increments
during the lifetime of the secret key that is protecting the packet.</para>
</glossdef>
</glossentry><glossentry id="glossary-93"><glossterm>reverse tunnel</glossterm><glossdef><para>A tunnel that starts at the mobile node's care-of address
and terminates at the home agent.</para>
</glossdef>
</glossentry><glossentry><glossterm>router</glossterm><glossdef><para>A system that usually has more than one interface, runs routing
protocols, and forwards packets. You can configure a system with only one
interface as a router if the system is the endpoint of a PPP link.</para>
</glossdef>
</glossentry><glossentry id="glossary-17"><glossterm>router advertisement</glossterm><glossdef><para>The process of routers advertising their presence together
with various link and Internet parameters, either periodically or in response
to a router solicitation message.</para>
</glossdef>
</glossentry><glossentry id="glossary-20"><glossterm>router discovery</glossterm><glossdef><para>The process of hosts locating routers that reside on an attached
link.</para>
</glossdef>
</glossentry><glossentry id="glossary-16"><glossterm>router solicitation</glossterm><glossdef><para>The process of hosts requesting routers to generate router
advertisements immediately, rather than at their next scheduled time.</para>
</glossdef>
</glossentry><glossentry id="glossary-59"><glossterm>RSA</glossterm><glossdef><para>A method for obtaining digital signatures and public key cryptosystems.
The method was first described in 1978 by its developers, Rivest, Shamir,
and Adleman.</para>
</glossdef>
</glossentry><glossentry id="glossary-132"><glossterm>SA</glossterm><glossdef><para>See <olink targetptr="glossary-51" remap="internal">security association (SA)</olink>.</para>
</glossdef>
</glossentry><glossentry id="glossary-58"><glossterm>SADB</glossterm><glossdef><para>Security Associations Database. A table that specifies cryptographic
keys and cryptographic algorithms. The keys and algorithms are used in the
secure transmission of data.</para>
</glossdef>
</glossentry><glossentry><glossterm>SCTP</glossterm><glossdef><para>See streams control transport protocol.</para>
</glossdef>
</glossentry><glossentry id="glossary-51"><glossterm>security association (SA)</glossterm><glossdef><para>An association that specifies security properties from one
host to a second host.</para>
</glossdef>
</glossentry><glossentry id="glossary-94"><glossterm>security parameter index (SPI)</glossterm><glossdef><para>An integer that specifies the row in the security associations
database (SADB) that a receiver should use to decrypt a received packet.</para>
</glossdef>
</glossentry><glossentry id="glossary-157"><glossterm>security policy database (SPD)</glossterm><glossdef><para>Database that specifies the level of protection to apply to
a packet. The SPD filters IP traffic to determine whether a packet should
be discarded, should be passed in the clear, or should be protected with IPsec.</para>
</glossdef>
</glossentry><glossentry id="glossary-111"><glossterm>selector</glossterm><glossdef><para>The element that specifically defines the criteria to be applied
to packets of a particular class in order to select that traffic from the
network stream. You define selectors in the filter clause of the IPQoS configuration
file.</para>
</glossdef>
</glossentry><glossentry id="glossary-62"><glossterm>SHA-1</glossterm><glossdef><para>Secure Hashing Algorithm. The algorithm operates on any input
length less than 2<superscript>64</superscript> to produce a message digest.
The SHA-1 algorithm is input to DSA.</para>
</glossdef>
</glossentry><glossentry id="glossary-14"><glossterm>site-local-use address</glossterm><glossdef><para>A designation that is used for addressing on a single site.</para>
</glossdef>
</glossentry><glossentry id="glossary-143"><glossterm>smurf attack</glossterm><glossdef><para>To use <olink targetptr="glossary-148" remap="internal">ICMP echo request packet</olink>s
directed to an IP <olink targetptr="glossary-145" remap="internal">broadcast address</olink> or
multiple broadcast addresses from remote locations to create severe network
congestion or outages. </para>
</glossdef>
</glossentry><glossentry id="glossary-154"><glossterm>sniff</glossterm><glossdef><para>To eavesdrop on computer networks&mdash;frequently used as
part of automated programs to sift information, such as clear-text passwords,
off the wire.</para>
</glossdef>
</glossentry><glossentry id="glossary-155"><glossterm>spoof</glossterm><glossdef><para>To gain unauthorized access to a computer by sending a message
to it with an IP address indicating that the message is coming from a trusted
host. To engage in IP spoofing, a hacker must first use a variety of techniques
to find an IP address of a trusted host and then modify the packet headers
so that it appears that the packets are coming from that host.</para>
</glossdef>
</glossentry><glossentry id="glossary-158"><glossterm>SPD</glossterm><glossdef><para>See <olink targetptr="glossary-157" remap="internal">security policy database
(SPD)</olink>.</para>
</glossdef>
</glossentry><glossentry id="glossary-52"><glossterm>SPI</glossterm><glossdef><para>See <olink targetptr="glossary-94" remap="internal">security parameter index
(SPI)</olink>.</para>
</glossdef>
</glossentry><glossentry id="glossary-151"><glossterm>stack</glossterm><glossdef><para>See <olink targetptr="glossary-138" remap="internal">IP stack</olink>.</para>
</glossdef>
</glossentry><glossentry id="glossary-72"><glossterm>standby</glossterm><glossdef><para>A physical interface that is not used to carry data traffic
unless some other physical interface has failed.</para>
</glossdef>
</glossentry><glossentry id="glossary-152"><glossterm>stateful packet filter</glossterm><glossdef><para>A <olink targetptr="glossary-142" remap="internal">packet filter</olink> that
can monitor the state of active connections and use the information obtained
to determine which network packets to allow through the <olink targetptr="glossary-46" remap="internal">firewall</olink>. By tracking and matching requests
and replies, a stateful packet filter can screen for a reply that doesn't
match a request.</para>
</glossdef>
</glossentry><glossentry id="glossary-22"><glossterm>stateless autoconfiguration</glossterm><glossdef><para>The process of a host generating its own IPv6 addresses by
combining its MAC address and an IPv6 prefix that is advertised by a local
IPv6 router.</para>
</glossdef>
</glossentry><glossentry><glossterm>stream control transport protocol</glossterm><glossdef><para>A transport layer protocol that provides connection-oriented
communications in a manner similar to TCP. Additionally, SCTP supports multihoming,
in which one of the endpoints of the connection can have more than one IP
address.</para>
</glossdef>
</glossentry><glossentry id="glossary-40"><glossterm>symmetric key cryptography</glossterm><glossdef><para>An encryption system in which the sender and receiver of a
message share a single, common key. This common key is used to encrypt and
decrypt the message. Symmetric keys are used to encrypt the bulk of data transmission
in IPsec. <olink targetptr="glossary-37" remap="internal">DES</olink> is one example of a symmetric
key system.</para>
</glossdef>
</glossentry><glossentry id="glossary-144"><glossterm>TCP/IP</glossterm><glossdef><para>TCP/IP (Transmission Control Protocol/Internet Protocol) is
the basic communication language or protocol of the Internet. It can also
be used as a communications protocol in a private network (either an intranet
or an extranet).</para>
</glossdef>
</glossentry><glossentry id="glossary-31"><glossterm>Triple-DES</glossterm><glossdef><para>Triple-Data Encryption Standard. A symmetric-key encryption
method. Triple-DES requires a key length of 168 bits. Triple-DES is also written
as 3DES.</para>
</glossdef>
</glossentry><glossentry id="glossary-95"><glossterm>tunnel</glossterm><glossdef><para>The path that is followed by a <olink targetptr="glossary-133" remap="internal">datagram</olink> while it is encapsulated. See <olink targetptr="glossary-55" remap="internal">encapsulation</olink>.</para>
</glossdef>
</glossentry><glossentry id="glossary-65a"><glossterm>unicast address</glossterm><glossdef><para>An IPv6 address that identifies a single interface of an IPv6-enabled
node. The parts of the unicast address are site prefix, subnet ID, and interface
ID.</para>
</glossdef>
</glossentry><glossentry id="glossary-112"><glossterm>user-priority</glossterm><glossdef><para>A 3-bit value that implements class-of-service marks, which
define how Ethernet datagrams are forwarded on a network of VLAN devices.</para>
</glossdef>
</glossentry><glossentry id="glossary-113"><glossterm>virtual LAN (VLAN) device</glossterm><glossdef><para>Network interfaces that provide traffic forwarding at the
Ethernet (data link) level of the IP protocol stack.</para>
</glossdef>
</glossentry><glossentry id="glossary-57"><glossterm>virtual private network (VPN)</glossterm><glossdef><para>A single, secure, logical network that uses tunnels across
a public network such as the Internet.</para>
</glossdef>
</glossentry><glossentry id="glossary-96"><glossterm>visited network</glossterm><glossdef><para>A network other than a mobile node's home network, to which
the mobile node is currently connected.</para>
</glossdef>
</glossentry><glossentry id="glossary-97"><glossterm>visitor list</glossterm><glossdef><para>The list of mobile nodes that are visiting a foreign agent.</para>
</glossdef>
</glossentry>
</glossary>