Networks Midterm Two

choosing a path to follow, based on IP addresses
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Terms in this set (129)
What is the most specific applicable entry to be used in a routing table?, kind of route is route--matches anythingAny address in the Loopback net goes to where? entry is a local subnet--this node can use ARP to send directly, so its own gateway? entry is the Global IP broadcast address? process for matching an IP address in a local network to an IP address on the InternetNetwork Address TranslationWhere do most NAT implementations appear?edge routers (home routers)What is the most common form of NAT, used in SOHO routers, and has single external IP address and multiple internal IP addresses?Overloaded NATWhat early version of NAT includes one-to-one matching of external IP addresses with internal addresses?StaticWhat early version of NAT has the router maintain a pool of external IP addresses and matches them to internal addresses temporarily?DynamicWhat do TCP and UDP(layer 4) assign to applications to identify them locally?port numbersCombination of host IP address and host port numbersocketHow are routing tables set up during static routing?by hand (internal router on a LAN)How are routing tables set up during dynamic routing?determined and maintained automatically, as connections changeWhich algorithm uses information about each router's neighboring routers? *sometimes called "routing by rumor"Distance Vector Algorithmwhich algorithm is a distributed algorithm--nobody computes an entire route?distance vectorWhich RIP is the original internet/ARAPAnet routing protocol? -max hop count=15RIPv1Which RIP, adopted in 1994, randomizes update intervals?RIPv2Which algorithm, at each step, has the router tell its immediate neighbors who it knows about and eventually, all router connections are shared to all routers?RIP's Distributed AlgorithmWhich protocols depend on each router knowing the entire network's topology? -announces only its immediate neighbors, but all routers get the informationLink-Statewhich algorithm has more computation, but less information must be exchanged?link stateWhat does OSPF stand for?Open Shortest Path FirstWhat protocol has links between routers that have associated costs?OSPFWhat is it called, in the first stage of OSPF, when each of the routers broadcasts "hello packets"?floodingWhat are hello packets a kind of?Link State Advertisement (LSA)Routers accept hello packets from other routers with the same what?Area IDWhat does the "Election Process" identify?one router as designated and another as backup designatedWhich OSPF packet type multicasts to establish communication with directly connected neighbors?hello packetswhat OSPF packet lists router IDs from which the router has an LSA and its current sequence number?database descriptorwhat OSPF packet is a request for an LSA?Link State Request (LSR)what OSPF packet is a reply to an LSR with the requested information?Link State Update(LSU)what OSPF packet is used to confirm receipt of link-state information?Link State Acknowledgement(LSAck)Which protocol is comparable to OSPF, uses a "link state PDU" in place of OSPF's "LSA", and not based on IP packets?IS-IS:What does IS-IS stand for?Intermediate System to Intermediate SystemWhat protocol combines characteristics of distance vector and link state and is a cisco proprietary protocol? "the Hybrid"EIGRPWhat does EIGRP stand for?Enhanced Interior Gateway Routing ProtocolWhat protocol is a form of distance-vector algorithm, supports a hierarchical structure for the internet, and routes between autonomous systems instead of individual routers?BGPWhat does BGP stand for?Border Gateway ProtocolWhat is it called when independent organizations connect to each other over the Internet? (orignally ARPAnet)Autonomous systemWhat does each AS consist of?multiple networks, connected by routers and assigned unique IP network addressesa set of routers under a single technical administration, using an interior gateway protocol and common metrics to route packets within the AS, and using an exterior gateway protocol to route packets to other AS'sAutonomous SystemEach autonomous system uses what to route between networks?Interior Gateway ProtocolAS communicate with each other via an what?Exterior Gateway ProtocolWhat size are the values of the autonomous systems numbers, identified in RFC-1930?16-bit valuesIn 2008, RFC-4893 introduced what size AS numbers and how are they written?32-bit "dotted decimal" notationWhat do computers need to make them accessible over a network?addressesHow do people identify computers?domain names corresponding to their network ID'sWhat matches domain names with IP addresses?Name resolutionNodes in a network have what corresponding to their host IDs?host nameswhat is the leftmost piece of the domain name?host namewhat isolates the host portion of the IP address?subnet maskT/F: Networks assign their own host addressesTrueWhat command do you use to find the host name? (same for Linux and Windows)hostnameWhat does DNS stand for?Domain Name SystemWhat type of name space is a list of distinct names and if a name is repeated, confusion arises?Flat name spaceWhat type of name space does Windows Networks use?Flat name spaceWhat type of name space organizes names into categories and is frequently shown as a tree structure?hierarchical name spaceWhat is the highest level of hierarchical name space called?Top-level domainswhat kind of TLDs does the internet use?standardized TLDsWhat are the levels in the hierarchy structure of DNS?Root Servers Top-Level Domain Servers Second-level Servers Local and private nameserversHow many root server names are there and how are they categorized?thirteen categorized "A" through "M"T/F: top-level domains are the last part of the domain nametrueWhat does FQDN stand for?Fully Qualified Domain NamesWhat is the maximum length for FQDNs?254 octets and 1 root dot=255Each domain or subdomain maintains an authoritative name server called what?Start of AuthorityWhat is the main purpose of SOA?Maintains a zone file listing all hosts in its (sub)domainWhat knows all SOAs in its network?Root name server(for a top-level domain)In this DNS hierarchy, domains at each level have what two things?One SOA One(or more) name-serversT/F: Each local name server belongs strictly to a hierarchyFalseEach ISP has one local name server called what?default name serverWhat is it called when a DNS client allows the DNS server to return the best answer it can give based on its cache or zone data?Pure Iterative Name LookupWhat is it called when the DNS client requires that the DNS server respond to the client with either the requested resource record or an error message stating that the record or domain name does not exist?Pure Recursive Name LookupIn what zone do resource records map domain names to IP addresses?Forward lookup zonesWhat zone allows reverse lookups--give the host name for an IP address?reverse lookup zonesA portion of the DNS namespace managed by a specific organizaiton...DNS zoneWhat maintains information about a zone?zone filesWhat is the format of a resource record?(name, value, type, ttl)In computer networking, this type of file is a text file that describes a portion of the domain name system called a DNS fileContains information that defines mappings between domain names and IP addresses and other resources, organized in the form of resource recordszoneIn a zone, where are are the mappings that are determined stored?resource recordsWhat does API stand for?Application Programmer InterfaceWhat three things does NetBIOS API provide?~Name registration, resolution service ~Connection-oriented session service ~Connectionless datagram serviceWhat service for NetBIOS is in Port 137? and is it UDP/TCP?NetBIOS Name Service UDPWhat Service for NetBIOS is in Port 138? UDP/TCP?NetBIOS Datagram Service UDPWhat service for NetBIOS uses Port 139? UDP/TCP?NetBIOS Session Service TCP (short sessions)What are the NetBIOS applications matched to the OSI model?7--Redirector 6--SMB 5--NetBIOS 4--NetBIOS,NetBEUI 3--NetBIOS, NetBEUI 2--NDIS 1--NICWhat does the Redirector do?sends network requests to application serverWhat does NDIS stand for?Network Drivers Interface SpecificationWhat organizes my computers into groups that can share, aka "My Network Places"?Windows WorkgroupWhat is the Windows Domain based on to run the Windows server?domain controller node--must authenticate to the domain controller to joinT/F: All domain controllers are also DNS serversTrueWhat is a distributed organization of domain controllers and its integrated zone allows all domain controllers to update DNS records?Active DirectoryWhat are the 6 types of Resource Records?SOA NS MX A(AAAA) CNAME PTRWhat type of server maintains records of NetBIOS names, the clients register directly with it instead of broadcasting and can accept routing registrations?WINS Servers (Windows Internet Name Service)Most DNS servers are..., they store DNS answers, based on a time-to-live valuecaching serversExtensions to DNS that provide authentication for clients are called what, in relation to DNS Security Extensions?resolversWhat troubleshooting technique can tell if IP address works when domain name doesnt?Pingwhat troubleshooting technique investigates what the DNS server sends back?nslookup; digHow long are IPv4 addresses?32 bits (2^32=about 4 billion addresses)T/F: there are more available address blocks to be given outFalse, they were all assigned as of 2011How many bits per address are there in an IPv6 address?128 bitsHow are IPv6 addresses split up?into eight 16-bit blocks and written block-by-block(separated by colons)What are two ways to shorten the notation of the IPv6 addresses?-drop leading zeros in a block -replace groups of zeros with : :How are IP addresses given out?-an IPv6-capable host assigns itself a Link-Local Address -Hosts on IPv6 networks are given an IPv6 prefix by the router they connect toWhat are the right-most 64 bits called in a link-local address?Extended Unique Identifier(EUI-64)Who assigns the global unicast addresses?default gateway routerCurrently, what do all global addresses begin with?2What is the IPv6 loopback address?::1What do all IPv6 multicast addresses begin with?ffWhat is the IPv6 address for the milticast address space?ff00::/8What is the IPv6 address for all the link-local nodes?ff02::1What is the IPv6 address for all link-local routers?ff02::2How are subnets formed and what do they start with?hierarchically -2000::/4How long is the basic IPv6 Extension header and what do they begin with?always 40 octets long -their own Next-Header fieldWhat is meant by router aggregation?lower-tier always route to a subnet of their higher-tier connections -a form of hierarchyWhat two modes are included in DHCPv6?Stateless and statefulWhat mode in DHCPv6 provides additional configuration information, such as DNS server addressesStatelessWhat mode in DHCPv6 manages address assignment in absence of aggregation--useful for unusual intranetsStatefulWhere are IPv6 addresses kept in comparison to IPv4 addresses?AAAA records instead of A records