Networking 3

When one DNS server receives a recursive request, that DNS server issues what are called ____ to the name servers in its hierarchy, or to servers provided as pointers in reply to earlier requests, until an answer is received. .caching queries .address queries .domain queries .iterative queries

iterative queries

Once a TCP connection is established, a ____ can maintain the connection when there is no data sent across the wire. watchdog process core services keep-alive process handshake process

keep-alive process

The Fast Recovery process dictates that when a host receives three duplicate ACKs, it must immediately start retransmitting which of the following without waiting for the retransmission timer to expire duplicate ACKs core services byte streams lost segments

lost segments

A(n) ____ record may be used to add arbitrary text information to a DNS database, usually for documentation. 1) well-known services 2) text 3) pointer 4) host information

Text

The ____________ is distinguished from other name servers for a domain by its ability to always read its data from a zone file on disk when the DNS service starts up

primary master

Most DNS resolvers issue which of the following from the client side? .recursive query .address query .nslookup .name query

recursive query

What type of query is known as a query that keeps working until an answer of some kind is forthcoming? .domain query .reverse query .recursive query .NSLOOKUP query

recursive query

The initial sequence number used in a TCP connection is defined by the which of the following and, for security purposes, should be randomly assigned? host packet port segment

host

A ____ occurs when a secondary server updates its database from the primary domain NS.

incremental zone transfer

A name query seeks to resolve an address to a domain name, and is also known as _______

inverse DNS query

The job of the DHCP ___ software is to intercept address requests on a local cable segment and repackage those requests as a unicast to one or more DHCP servers.

relay agent

Which resource record lists the IP-based services, such as Telnet, FTP, HTTP, and so forth, that an Internet host can supply? .well-known services .text .name server .host information

well-known services

____ use dynamic IP addresses because they initiate the connections to the servers, and the servers simply respond to the clients based on the clients' IP addresses.

Clients

The structure of the DNS database mirrors the structure of the domain namespace itself.

True

When a TCP/IP client uses a resolver to send a name query to a DNS server, that client obtains the address for the DNS server it queries from its TCP/IP configuration data

True

When the Protocol field of an IP header contains the value 17 (0x11), the UDP header follows the IP header

True

The ____ packet is sent from the server to the client to indicate the completion of the four-packet DHCP Discovery process.

Acknowledgement packet

A DNS resource record that maps IPv4 addreses to hosts within a domain. Address (A) record Link-Local Multicast Name Res Peer Name Res Protocol caching-only server CNAME record SOA record delegation of authority multihomed pointer record

Address (A) record

When a DHCP client boots up, it performs a Standard ____ to enable it to communicate on the network.

Address Discovery

DHCP servers can manage one or more ranges of IP addresses, each of which may be called a(n) ____.

Address pool

DHCP traces its origins back to an earlier protocol named

BOOTP

____ was developed in the 1970s as a way to provide sufficient network access so diskless workstations could access startup information across the network, instead of reading it from a local disk drive.

BOOTP

TCP has four defined congestion control mechanisms to ensure the most efficient use of ____________________ along with quick error and congestion recovery.

Bandwidth

The DNS RR used to define database aliases, primarily to make it quicker and easier to edit and manage DNS zone files. Record Link-Local Multicast Name Res Peer Name Res Protocol caching-only server CNAME record SOA record delegation of authority multihomed pointer record

CNAME record

A type of server that is used only to cache already resolved domain names and addresses, as well as related error information Record Link-Local Multicast Name Res Peer Name Res Protocol caching-only server CNAME record SOA record delegation of authority multihomed pointer record

Caching only server

Which of the following processes permits a DNS server to keep track of which IP addresses it has provided most recently for a specific translation and to rotate the IP addresses within the pool? .ip spoofing .name resolution .FQDN .DNS round robin

DNS round robin

____ is a service that provides a way for a client computer that lacks an IP address assignment to request one from any listening DHCP server - without the help of an administrator.

DHCP

The ____ software, or other similar software available for most other modern operating systems, is enabled at a client machine when you select the Obtain an IP address automatically option in the Internet Protocol (TCP/IP) Properties window.

DHCP client

If no DHCP server is present in some broadcast domain, a special piece of software called a(n)____ must be present in that broadcast domain.

DHCP relay agent

Which of the following defines the destination application or process that uses the IP and UDP headers? checksum field value dynamic port number field value length field value destination port number field value

Destination port number field value

A type of DHCP address lease in which each address allocation comes with an expiration timeout so address leases must be renewed before expiration occurs or a new address will have to be allocated instead. Used primarily for client machines that do not require stable IP address assignments.

Dynamic address lease

The ____ flag is used to indicate that the host completed a transaction. Reset flag FIN flag SYN flag URG flag

FIN

Clients have static IP addresses because their DNS entries must stay consistent

False

Clients have static IP addresses because their DNS entries must stay consistent.

False

Not all the data in a DNS cache has an expiration value.

False

TCP keep-alives are enabled by default on Windows XP, Windows Vista, Windows 7, Windows Server 2003, and Windows Server 2008, although any application may disable TCP keep-alives, if desired by its programmer

False

The DHCP specification, RFC 2131, defines the default value for T1 as 0.95*duration_of_lease.

False

Twenty-six root name servers (named A.ROOT-SERVERS.NET., B.ROOT-SERVERS.NET., etc.) act as the top of the DNS hierarchy worldwide. They provide the ultimate source for all name lookups that cannot be resolved through other means.

False

UDP offers connection-oriented services with sequencing, error recover, and a sliding window mechanism

False

The ____ field is set to 0 by the client and may be used by relay agents as they assist a client in obtaining an IP address and/or configuration information.

Hops

The ___ packet includes the IP address that is offered to the client end, sometimes, answers to the requested options in the DHCP Discover packet.

Offer

A protocol that provides name resolution services on local networks for IPv4 and IPv6 Windows computers. Address record Link-Local Multicast Name Res Peer Name Res Protocol caching-only server CNAME record SOA record delegation of authority multihomed pointer record

Link-Local Multicast Name Res

In a DHCP Discover packet, what is the client identifier field based on?

MAC address

With a(n) ____ the administrator explicitly assigns an IP address manually by associating a client's hardware address with a specific IP address to be leased to that client.

Manual address lease

A name resolution protocol used for peer-to-peer network environments and that provides secure and scalable resolution services. Record Link-Local Multicast Name Res Peer Name Resolution Protocol caching-only server CNAME record SOA record delegation of authority multihomed pointer record

Peer Name Resolution Protocol

The DNS resource record that's used for inverse lookups to map numeric IP addresses to domain names. Record Link-Local Multicast Name Res Peer Name Res Protocol caching-only server CNAME record SOA record delegation of authority multihomed pointer record

Pointer record

Which type of request will always go to the name server that is authoritative for the domain that contains the requested name or address to make completely sure data is obtained directly from the source? .root server .client server .mail server .cache server

Root server

____ have static IP addresses because their addresses are key parts of any subnet's IP configuration

Routers

The DNS resource record that's mandatory in every DNS zone file; it identifies the server or servers that are authoritative for the domain or subdomain to which the zone files or database correspond. Record Link-Local Multicast Name Res Peer Name Res Protocol caching-only server CNAME record SOA record delegation of authority multihomed pointer record

SOA record

____ is defined as the time that the client tries to renew its network address by contacting the DHCP server that sent the original address to the client.

T1

Is defined as the time that the client begins to broadcast a renewal request for an extended lease time from another DHCP server.

T2

Because of ____________________'s end-to-end reliability and flexibility, it is the preferred transport method for applications that transfer large quantities of data and require reliable delivery services.

TCP

The ____________________ pseudo-header consists of three fields taken from the IP header: the IP Source Address field value, the IP Destination Address field value, and the Protocol field value.

TCP

An application or service that encounters a domain name for which it needs an IP address is known as which of the following? .address request .TCP/IP client .caching server .DNS client

TCP/IP client

an amount of time that a TCP host must not use connection parameters after closing down that connection timeout mechanism temporary port Time Wait delay TCP bufer area retransmission timer Nagle algorithm Sequence number tracking acknowledgement windowing

Time Wait delay

The ____ field contains a random number selected by the client and is used to match requests and responses between the client and server.

Transaction ID Number

Clients ordinarily attempt to renew existing releases by default, but you can instruct a DHCP server to deny lease renewals, or even cancel leases, when necessary.

True

DHCP can exclude individual addresses or address ranges from dynamic allocation to client machines.

True

DHCP delivers the necessary configuration information to clients to tell them addresses of their IP gateways.

True

Domains (such as ibm.com) can be broken into subdomains (such as clearlake.ibm.com), as needed.

True

TCP half-open connections occur when the handshake process does not end successfully with a final ACK.

True

During the DHCP Discovery process, the client broadcasts a Discover packet that identifies the client's _____________

hardware address

The ___ field contains the address being offered by the DHCP server.

Your IP address

The ____ packet is sent from the server to the client to indicate the completion of the four-packet DHCP Discovery process.

acknowledgement

What are the files called that map addresses to domain names for reverse lookups? tree.dn domain.dns addr.in-addr.arpa.dns clearlake.dns

addr.in-addr.arpa.dns

A __________ seeks to resolve a domain name to a corresponding numeric IP address: it simply provides a symbolic domain name, and expects a numeric IP address in return

address request

Overloading a receiver occurs when the number of data bytes is greater than this. advertised window bandwidth sliding window ephemeral port

advertised window

The DHCP ____ process relies heavily on broadcasts, but most routers do not forward broadcasts.

boot

Which process provides a mechanism whereby DNS can attempt to satisfy name resolution requests locally before attempting them remotely, thereby greatly improving the speed of such name resolution?

caching

What is used in order for TCP hosts to create a virtual connection with each other? sliding window handshake process teardown sequence retry mechanism

handshake process

____ store recently accessed DNS records from other domains to avoid incurring the performance overhead involved in making a remote query each time a resource outside the local domain is accessed. .name resolvers .primary DNS servers .subdomains .caching servers

caching servers

Which type of resouce record is used to create aliases? .canonical name .host information .name server .pointer

canonical name

Which of the folowing is detected whenever three or more duplicate ACK packets (known as triple ACK) or timeout events occur, and timeout events are considered more serious than duplicate acknowledgements? logical connection congestion retransmission windowing

congestion

____ is the overloading of the network or a receiver. sequence number tracking buffering congestion windowing

congestion

____ provide the simplest kind of transport services because they simply package messages, taken as is from the TCP/IP Application layer, into datagrams. Core services port numbers logical connections connectionless protocols

connectionless protocols

The ____________________ window is always the lesser of what the network and receiver can handle.

current

The records in the _____ file are provided to support reverse DNS lookups. arpa.addr db.addr cname.addr dns.addr

db.addr

the principle whereby one name server designates another name server to handle some or all of the zone files for the domain or subdomains under its purview Record Link-Local Multicast Name Res Peer Name Res Protocol caching-only server CNAME record SOA record delegation of authority multihomed pointer record

delegation of authority

A(n) ____ is used to assign addresses to clients or other machines when fixed IP addresses are not required.

dynamic address lease

The TCP connection termination process requires how many packets? one two three four

four

Which record is used to route SMTP-based e-mail on the Internet and identify the IP address for a domain's master e-mail server? .canonical name .mail exchange .name server .pointer

mail exchange

Containing multiple network interfaces capable of attaching to multiple subnets. Address record Link-Local Multicast Name Res Peer Name Res Protocol caching-only server CNAME record SOA record delegation of authority multihomed pointer record

multihomed

Which of the following is responsible for initiating and sequencing DNS queries that result in name resolution for an application running on the computer .name resolver .subdomain .primary master .caching server

name resolver

DNS servers cache name and address pairs for addresses they resolved, and they keep information about name requests that result in error messages. This kind of information is called ____. .DNS round robin .name resolution .negative caching .IP spoofing

negative caching

Which command is used to show active TCP connections, listening ports, Ethernet statistics, IPv4 statistics, and IPv6 statistics. .nslookup .route .netstat .dnscmd

netstat

Which command is an essential tool for testing when configuring or troubleshooting a DNS server? .nslookup .route .netstat .dnscmd

nslookup

Which type of resource record stores IP address-to-domain name translation data and supports the operation known as a reverse DNS lookup? .well-known services .text .pointer .host information

pointer

It is important to understand that the zone data on a secondary server always originates from a(n) ____ server. .caching .incremental .name .primary

primary

It is important to understand that the zone data on a secondary server always originates from a(n) ____ server. caching incremental name primary

primary

The command ______, in the IPCONFIG utility, releases the IP address for the specified adapter

release

Data associated with domain names, address records, and other specific data of interest to the Domain Name System is stored on a DNS server in special database records called ____. hosts resouce records zones primary master

resource records

Data associated with domain names, address records, and other specific data of interest to the Domain Name System is stored on a DNS server in special database records called ____. .hosts .resouce records .zones .primary master

resource records

A(n) ____ gets its data for the zone from the master server for that zone.

secondary DNS server

the DHCPv6 server maintain awareness of the status or state of its pool of available addresses, the presence or absence on the network of permitted clients, and a variety of other parameters 1. stateful autoconfiguration 2. relay agent process 3. dynamic address lease 4. dhcp options 5. renewel process 6. dhcp discovery 7. stateless autoconfiguration 8. release preferred address

stateful autoconfiguration

Which of the following DHCP creations does Microsoft Windows Server 2012 R2 support?

superscope

____ are a collection of scopes that contain sets of non-consecutive IP addresses that can be assigned to a single network, but are also used with contiguous public class "C" addresses in supernetting scenario or when CIDR is in effect.

superscopes

A(n) ____ record may be used to add arbitrary text information to a DNS database, usually for documentation. well-known services text pointer host information

text