Final Exam Keywords
1. 802.3z – Gigabit Ethernet (1000 MBPS) originally defined 802.3z is referred to as 1000BASE-X, where -X refers to either -CX,
-SX, -LX, or -ZX.
2. Backdoor - backdoor is a connection between devices in the same layer, as shown in Figure 5-6.A backdoor can be an extra router, bridge, or
switch added to connect two networks.Abackdoor can also be a hub.
3. Autonomous System -Collection of networks or areas under a common administration sharing a common routing strategy.
4. RTT -round-trip time. Time required for a network communication to travel from the source to the destination and back. RTT includes the time
required for the destination to process the message from the source and generate a reply.
5. Traceroute -Program available on many systems that traces the path a packet takes to a destination.
6. Ping -ICMP echo message and its reply. Used in IP networks to test the reachability of a network device. 2
7. OSI –Network architectural model that consists of seven layers, each of which specifies particular network functions such as addressing, flow
control, error control, encapsulation, and reliable message transfer.
application layer, data link. layer, network layer, physical layer, presentation layer, session layer, and transport layer.
8. Broadcast domain -The set of all devices that receives broadcast frames originating from any device within the set. Broadcast domains are
bounded by routers (which do not forward broadcast frames). Aswitch or hub does not bound a broadcast domain.
9. Redundancy -The duplication of devices, services, or connections so that, if a failure occurs, the redundant devices, services, or connections
can perform the work of those that failed.
10. NAT -NetworkAddress Translation. Mechanism for reducing the need for globally unique IP addresses. NAT allows an organization with
addresses that are not globally unique to connect to the Internet by translating those addresses into globally routable addresses.
11. Maximum number of hops RIP and RIP-2 is 15
12. Dijkstra Algorithm-8- link-state routing protocol uses shortest path first algorithm to determine how to reach destination. The
result is a database topology called the link-state database. Each router in an area has an identical database. All routers run in
parallel. From link-state, each router constructs a tree of shortest paths with itself as the root of the tree. Shortest path tree provides
the route to each destination.
13. IPv4 Private Address Space -20
14. IPv6 Private Address Space -40
15. PAP -Password Authentication Protocol.Authentication protocol that allows PPP peers to authenticate one another. Unlike CHAP, PAP passes
the password and hostname or username in clear text (unencrypted).
16. CHAP -Challenge Handshake Authentication Protocol. Security feature supported on links using PPP encapsulation that identifies the remote
end of a PPP session using a handshake protocol and a variable challenge value that is unique and unpredictable.
17. RIP-2 - RIPv2 also supports simple authentication to foil hackers sending routing updates. The authentication scheme uses the space of a
route entry. This means that there can be only 24 route entries in a message when authentication is used. Currently, the only authentication
supported is a simple plain-text password.
18. Network Providers Tiers Classification (ch.5) –ISPs and NSPs are classified as being Tier1 through Tier5. Tier 1 ISPs are
large, international providers whereas Tier5 ISPs are small, specialized providers located in a town or rural area. Difference b/w the
tier has to do with the relationship a provider has with other ISPs. Tier1: doesn’t buy transit, has a 14/7 network operations center
and a national backbone with at least DS-3 connectivity. Tier2: have high bandwidth backbones and 24/7 operations but they are
limited to a regional or national presence and they buy transit from a Tier 1 provider for traffic that goes outside the region. Gets all
its regional routes through peering arrangements.
Tier3: typically a regional provider for a small/medium sized region. Buys transit from multiple upstream providers and runs a
default-free routing table. Tier 4: metropolitan provider that is multihomed to two regional providers. Tier5: small, single-homed
provider that connects end users via a wireless or cable modem service
19. Wiring - vertical wiring runs between floors. Horizontal wiring runs from telecommunications closets to wallplates in cubicles or offices.
Work-area wiring runs from the wallplate to a workstation in a cubicle or office.
20. Long-Reach Ethernet - which can be used to connect buildings and rooms within buildings in campus networks. LRE provides a point-to-
point link that can deliver a symmetrical, full-duplex, raw data rate of 11.25 Mbps over distances of up to 1 mile (1.6 km).
21. Metro Ethernet - Metro Ethernet is a service offered by providers and carriers that traditionally had only classic WAN offerings, such as
dialup, T1, and Frame Relay. Metro Ethernet blends the capabilities and behavior of WAN technologies with those of Ethernet.
22. Three-Part Firewall Topology (Chapter 5) & 23. DMZ Firewall Topology (Chapter 5)
24. Bandwidth Domain -compete for bandwidth. Bandwidth domains are bounded by switches, bridges, or routers. Ahub or repeater does not
bound a bandwidth domain. Also called a collision domain on Ethernet networks.
25. SNMP Trap - Notifications/alerts generated and transmitted by active network components (e.g. hubs, routers and bridges) to
SNMP server(s) whenever important events such as faults or security violations occur
26. Static Routing- Route that is explicitly configured and entered into a routing table.
27. BGP-4 -BGPVersion 4 (BGP4) is the predominant interdomain routing protocol used on the Internet.
28. DHCP -Dynamic Host Configuration Protocol. Provides a mechanism for allocating IP addresses dynamically to minimize configuration and
allow addresses to be reused when hosts no longer need them.
29. Access Layer -One of three layers in a hierarchical network topology, provides users on local segments access to the internetwork.