Internet Protocol (Part 2) Flashcards

Flashcards covering key concepts from the lecture on Internet Protocol Part 2.

Gift (in the context of technology)

Something voluntarily transferred by one person to another without compensation; a notable capacity, talent, or endowment.

IP service model

An addressing scheme to identify an IP host, and a datagram (connectionless) model of data delivery; provides a best-effort, unreliable service.

Types of IPv4 Addresses

Unicast, private, link-local, loopback, public, broadcast, multicast, anycast.

Private IPv4 Addresses

192.168.0.0 - 192.168.255.255, 172.16.0.0 - 172.31.255.255, 10.0.0.0 - 10.255.255.255

Loopback IPv4 Addresses

127.0.0.0/8

Link-Local IPv4 Addresses

169.254.0.0 – 169.254.255.255

Fields in IPv4 Datagram

Version, IHL, Type of Service, Total Length, Identification, Flags, Fragment Offset, Time to Live, Protocol, Header Checksum, Source Address, Destination Address, Options, Padding

Time to Live (TTL)

Limits the number of times that a datagram is processed by routers.

Protocol Field in IPv4

Specifies the type of payload, e.g., 6 for TCP and 17 for UDP.

Evolutions to IPv6

Longer IP addresses, more items in header, no options, no hop-by-hop fragmentation, end-to-end fragmentation, no error detection for headers.

IPv6 Header Fields

Version, Traffic Class, Flow Label, Payload Length, Next Header, Hop Limit, Source Address, Destination Address

IPv6 Address Types

Global Unicast, Link-Local Unicast, Loopback, Unspecified, Unique Local, Embedded IPv4, Multicast, Anycast

Main Services Provided by ICMP

Error reporting, reachability test, congestion control, route-change notification, time stamping, subnet addressing, router advertisement and solicitation.

ICMP Query Messages

Echo request and reply (Ping), router advertisement and solicitation, timestamp request and reply, address mask request and reply.

Content of ICMP Error Message

Contains the IP header and the first 8 bytes of payload of the IP datagram that caused the ICMP error to be generated.

MTU

Maximum Transmission Unit; the maximum network-layer packet size that can be sent on a data-link network.

Use of MTU

To send datagrams to a directly attached host, use the network’s MTU; to send datagrams to a non-directly attached host, use the path MTU.

Path MTU

The minimum of the networks’ MTUs on the path from the source to destination.

Packet Reassembly

A fragmented IP datagram will be reassembled only at the destination node; each fragment contains sufficient information for reassembly.

Components of IP Subnets

Network address, a subnet ID, and a host ID.

Subnet Mask

Indicates which bits are referred to the network and subnet ID.

IP Supernet

Have a subnet mask shorter than the network address.

Construction of Routing Tables

Routing tables for routers are constructed from routing protocols; routing tables for hosts are self constructed.

Characteristics of IP Forwarding

Both hosts and routers are involved; done on a hop-by-hop basis; able to specify a route to a network.

How a host sends a datagram

If on the same LAN (local), it sends the datagram to the destination directly; if on different LAN (remote), it sends the datagram to a default router.