3 - Fundamentals of WANs and IP Routing Flashcards
ARP
Address Resolution Protocol. An Internet protocol used to map an IP address to a MAC address. Defined in RFC 826.
default router (default gateway)
On an IP host, the IP address of some router to which the host sends packets when the packet’s destination address is on a subnet other than the local subnet.
DNS
DNS
Domain Name System. An application layer protocol used throughout the Internet for translating hostnames into their associated IP addresses.
Ethernet Line Service (E-Line)
A specific carrier/metro Ethernet service defined by MEF (MEF.net) that provides a point-to-point topology between two customer devices, much as if the two devices were connected using an Ethernet crossover cable.
HDLC
High-Level Data Link Control. A bit-oriented synchronous data-link layer protocol developed by the International Organization for Standardization (ISO).
hostname
The alphanumeric name of an IP host.
IP packet
IP packet
An IP header, followed by the data encapsulated after the IP header, but specifically not including any headers and trailers for layers below the network layer.
IP subnet
IP subnet
Subdivisions of a Class A, B, or C network, as configured by a network administrator. Subnets allow a single Class A, B, or C network to be used instead of multiple networks, and still allow for a large number of groups of IP addresses, as is required for efficient IP routing.
leased line
leased line
A serial communications circuit between two points, provided by some service provider, typically a telephone company (telco). Because the telco does not sell a physical cable between the two endpoints, instead charging a monthly fee for the ability to send bits between the two sites, the service is considered to be a leased service.
ping
ping
An Internet Control Message Protocol (ICMP) echo message and its reply; ping often is used in IP networks to test the reachability of a network device.
routing protocol
routing protocol
A set of messages and processes with which routers can exchange information about routes to reach subnets in a particular network. Examples of routing protocols include Enhanced Interior Gateway Routing Protocol (EIGRP), Open Shortest Path First (OSPF), and Routing Information Protocol (RIP).
routing table
routing table
A list of routes in a router, with each route listing the destination subnet and mask, the router interface out which to forward packets destined to that subnet, and as needed, the next-hop router’s IP address.
subnetting
subnetting
The process of subdividing a Class A, B, or C network into smaller groups called subnets.
telco
A common abbreviation for telephone company.
wide-area network (WAN)
wide-area network (WAN)
A part of a larger network that implements mostly OSI Layer 1 and 2 technology, connects sites that typically sit far apart, and uses a business model in which a consumer (individual or business) must lease the WAN from a service provider (often a telco).
