ISM4220 Ch 8

a 32-bit series with a number of 1s followed by the number of 0s. the number of 1s corresponds either to the packet's network part or network plus the subnet part. used by routers to assign routes to all packets going to a particular network or subnet on a network:

IPv4 Mask.

a standardized way of representing an IP address for condensed human reading:

IPv6 canonical text representation.

the first header in an IPv6 packet. other headers may follow. these are the extension headers. the data field follows the last extension header:

IPv6 main header.

a TCP flag field; if set, the TCP segment tells the other party that the sender is breaking the connection:

RST.

TCP segment in which the RST flag bit is set (1):

TCP reset segment.

in TCP, a header field that tells what TCP segment is being acknowledged in a segment:

acknowledgement number field.

an acknowledgment message, sent by the receiver when a message is received correctly:

acknowledgment (ACK).

a router that sits at the edge of a site to connect the site to the outside world through leased lines, PSDNs, and VPNs:

border router.

in routing, a list a router keeps of recent decisions for specific IP addresses so that it does not have to go through an entire routing decision again if another packet to that IP address arrives. this is nonstandard and somewhat risky:

decision cache.

the next-hop router that a router will forward a packet to if the routing table does not have a row that governs the packet's IP address except for the default row:

default router.

the row of a routing table that will be selected automatically if no other row matches; its value is 0.0.0.0:

default row.

field that specifies the quality of service that a packet should receive:

differentiated services control point.

the field in an IP packet that can be use to label IP packets for priority and other service parameters:

diffserv (differentiated services).

field that notifies the receiver that there is congestion on the network; the receiver may respond by reducing its transmission rate:

explicit congestion notification (ECN).

in IPv6, a header that follows the main header:

extension header.

a one-bit field:

flag field.

in IPv6, all packets in a stream of packets are given the same flow label number:

flow label field.

in IP addresses, three multiple parts that represent successively more specific locations for a host:

hierarchy.

in IPv6, the field that limits the number of hops an IPv6 packet may make among routers:

hop limit field.

the part of an IP address that identifies a particular host on a subnet:

host part.

a router that connects different LANs within a site:

internal router.

a number describing the desirability of a route represented by a certain row in a routing table:

metric.

the part of an IP address that identifies the host's network on the internet:

network part.

in an IPv6 main or extension header, the field that specifies the next header's type or specifies that the payload follows the header:

next header field.

a router to which another router forwards a packet in order to get the packet a step closer to reaching its destination host:

next-hop router.

in IPv6 packets, a field that gives the length of everything following the main header, including subsidiary headers:

payload length field.

a way of representing masks. gives the number of initial 1s in the mask:

prefix notation.

in IP, a field that designates the protocol of the message in the IP packet's data field:

protocol field.

an organization recognized by the internet assigned number authority; it receives a network part:

recognized organization.

processing an individual packet and passing it closer to its destination:

routing.

in TCP, a header field that tells a TCP segment's order among the multiple TCP segments sent by one side:

sequence number field.

the part of an IP address that specifies a particular subnet within a network:

subnet part.

a small network that is a subdivision of a large organization's network:

subnet.

the field added to a packet and given a value by a source host, usually between 64 and 128:

time to live (TTL) Field.

an IPv6 field for specifying special handling for a packet:

traffic class field.

in IP packets, the first field; it tells whether the packet is an IPv4 packet or an IPv6 packet:

version number field.