8_Name Resolution on IP Netks
Technique of configuring how a DNS server responds to requests for name-to-address resolution where one domain name corresponds to multiple IP addresses.
DNS round robin
Can be primary for one DNS database zone and can also be secondary for one or more other DNS database zones.
DNS server
Has these valid aspects: local control over domain name database segments | data from all database segments, available everywhere | highly robust and available database information.
Domain Name System
DNS database record used to identify all DNS servers in a domain. (ABBRV)
NS
Query sequences that represents a typical DNS lookup.
Recursive, then iterative
Is usually some application or service that encounters a domain name for which it needs an IP address.
TCP/IP client
DNS database record used to add arbitrary text information to an DNS database, usually for documentation. (ABBRV)
TXT
In Windows 7, this setting uses whatever NetBIOS setting is provided dynamically by DHCP or if the computer uses a static IPv6 address, automatically use NetBIOS over TCP/IP.
default NetBIOS
Is the process where a DNS server higher in the domain name hierarchy confers responsibility for portions of the global DNS database on DNS servers lower in its hierarchy.
delegation of authority
In a Windows environment, these provide AD services or other capabilities related to defining and applying group policy mechanisms, access controls, user and account information, and so forth.
domain controllers
DNS maintains its data on a large collection of name servers around the Internet by carving the domain namespace into a disjointed collection of ___ or ___.
domain or subdomain
___ (such as ibm.com) can be broken into smaller segments(such as clearlake.ibm.com), as needed.
domains
IPv6 networks use DNS ___ but must be able to work in hybrid IPv4-IPv6 environments.
extensions
Is the primary benefit of caching DNS data.
faster lookups
Consists of all elements of a domain name, in which each is followed by a period and the final period stands for the root of the DNS hierarchy itself. (HINT: FQDNS)
fully qualified domain names
DNS arose from the difficulty of maintaining static ___ files for computers on the ARPANET.
hosts
Windows operating system supports a variety of name resolution technologies, such as these:
hosts files, NetBIOS, WINS, and DNS
Is the name of the reverse hierarchy tree for DNS extensions in an IPv6 environment.
ipv6.arpa
Type of query issued by the DNS server to the name servers in its hierarchy, or to servers provided as pointers in reply to earlier such requests, until an answer is received, when one DNS server receives a recursive request.
iterative queries
A caching-only DNS server is most likely to benefit this type or size organization.
large, service provider
A record used to route SMTP-based e-mail on the Internet and identify the IP address for a domain's master e-mail server.
mail exchange
The piece of software that accesses DNS name servers on behalf of the network client.
name resolvers
Process where DNS servers cache name and address pairs for addresses they resolved, and keep information about name requests that result in error messages.
negative caching
Where requests 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
For Windows computers, IPv6 destination address selection may interfere with this IPv4 DNS destination address process.
round robin
It is not mandatory to have one or more of these for any DNS database zone.
secondary DNS servers
For each zone, one or more ___ may be created.
secondary name servers
Domain or subdomain databases, also known as database ___ or database ___, each of which belongs to a single authoritative name server for that zone.
segments, zones
Active Directory (AD) clients and domain controllers use these records to determine IP addresses for (other) domain controllers. This record type is described in RFC 2052. (HINT: two words)
service location
WINS--TTL default for the name. (days)
six days
Every zone file must include a ___ record to identify the name server that's primarily responsible for the database segments it manages.
start of authority
This method of name resolution was used by the Internet prior to the introduction of DNS.
static name resolution
This record may be used to add arbitrary text information to a DNS database, usually for documentation.
text
___ 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.
thirteen
WINS--if the node received the default TTL, it attempts to renew the name at half the TTL value. (days)
three days
Two- and three-letter country codes as well as organizational codes, such as .com, .edu, and .org are included.
top-level domain names
In a LLMNR exchange, the responding node answers the query, but only if it is authoritative for the name in the query. It responds with this type of UDP packet to the sending node.
unicast
This DHCP database record lists the IP-based services, such as Telnet, FTP, HTTP, and so forth, that an Internet host can supply.
well-known services
This and AD are part of a network's infrastructure, where important relationships between AD and DNS are typical and necessary.
windows servers
For each ___, a primary name server is mandatory; it contains the master copy of the database for its ___. (same term for both blanks)
zone
An IPv6 computer with two different network interfaces, each connected to a different subnet--is an example.
zone ID
Each interface can have identical IPv6 link-local addresses but use different ___.
zone ID
DNS database record used to route SMTP-based e-mail on the Internet and identify the IP address for a domain's master e-mail server. (ABBRV)
MX
Is the maximum number of primary database servers allowed in any single DNS database zone.
1
DNS database record that stores domain name-to-IP address translation data. (ABBRV)
A
Some DNS resolvers default to looking up ___ records first and may time out before looking up AAAA records.
A
This DNS resource record maps domain names to IPv4 host addresses.
A
IPv6 host addresses use this DNS resource record.
AAAA
In an IPv6 environment, DNS servers store name resolution data these records rather than in A records. DNS servers and resolvers must maintain both types of records.
AAAA
DNS resource records and error messages are the kinds of data most likely to show up in a response to this type of query.
DNS query of any kind
DNS database record used to create aliases. (ABBRV)
CNAME
Provides the key address resolution service that makes today's Internet possible.
DNS
Was designed to create a flexible, reliable, and robust name and address resolution service that could handle very large address spaces.
DNS
All ___ data has an expiration value.
DNS cache
Its structure mirrors the structure of the domain namespace itself.
DNS database
DNS database record that stores descriptive information about a specific Internet host. (ABBRV)
HINFO
Algorithms are written to work in the IPv6 address space, but they also affect how ___ address selection operates.
IPv4
Uses a source address selection algorithm and a destination address selection algorithm to provide source and destination address selection.
IPv6
-RFC 4795 -Allows IPv4 and IPv6 network nodes to perform name resolution for other devices connected to the same local link. -Is a protocol based on the DNS packet format. -Messages can be sent using TCP but is not supported by Windows Vista.
LLMNR
LLMNR
Link-Local Multicast Name Resolution
DNS database record that stores IP address-to-domain name translation data and supports the operation known as reverse DNS lookup. (ABBRV)
PTR
This protocol is supported by Windows XP SP2, Windows Vista, Windows 7 WRA, and Windows Server 2008, but not by any edition of Windows Server 2003.
Peer Name Resolution Protocol
A, CNAME, HINFO, MX, NS, PTR, SOA, SRV, TXT, WKS are the nine most commonly used __ types.
RR (Resource Records)
RR
Resource Records
DNS database record that identifies the name server that is authoritative for a specific DNS database segment. (ABBRV)
SOA
DNS database record, sometimes simply called a Service record, is designed to provide information about available services and used in the Windows Active Directory environment to map the name of a service to the name of a server that offers such service. (ABBRV)
SRV
This WINS message acknowledges the receipt of the Name Registration Request packet without either granting or denying it, but asks the node to wait. (ABBRV)
WACK
When a node, user, or process with a NetBIOS name signs on to the network or starts up, it attempts to register its name. If the name already exists in the database, the WINS server sends this message type to the node attempting to register. (ABBRV)
WACK
Service that resolves NetBIOS names to IP addresses in routed networks
WINS
DNS database record that lists the IP-based services (Telnet, FTP, HTTP, and so forth) that an Internet host can supply. (ABBRV)
WKS
WACK
Wait Acknowledgement
WINS
Windows Internet Name Service
These software can read "http://2001:db8-adc2-2131.ipv6.literal.net" names.
Windows and any legacy
Is the kind of environment Link-local Multicast Name Resolution protocol works in.
a single subnet
Name of files that map addresses to domain names for reverse lookups. [addr.in-addr.arpa.dns | tree.dn | domain.dns | clearlake.dns]
addr.in-addr.arpa.dns
IPv6 source and destination address selection is managed by ___ that use a set of rules to determine how the selection process is managed.
algorithms
Are where all DNS queries end because it can access any and all authoritative name servers for any database segment.
at the root
WINS servers can go into ___ to prevent the WINS server from being overwhelmed by a sudden spike in utilization.
burst mode
By ____ DNS data from one or more database segments on one or more DNS servers, DNS also provides a mechanism whereby it can attempt to satisfy name resolution requests locally before attempting them remotely, thereby greatly improving the speed of such name resolution.
caching
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.
caching servers
Any type of DNS server cannot also be this type of server.
caching-only
For large or heavily trafficked networks, ___ name servers offload the task of resolving names and addresses outside the local zones for users.
caching-only
Windows ___ computers use DNS resolvers to issue service requests to DNS servers for name resolution.
client
DNS was designed as a distributed database; individual portions of such databases, include (or define) only a portion of the overall namespace that DNS can access for its clients.
database segments
This file's records are provided to support reverse DNS lookups. [arpa.addr | cname.addr | db.addr | dns.addr]
db.addr
If your ISP and primary DNS server do not support IPv6 and you type ___ www.ipv6.cisco.com at the interactive prompt, the DNS request may time out without returning the desired data.
nslookup
This command provides access to all kinds of DNS information, either from the current default server, or from a server whose name or IP address you provide as an argument to this command.
nslookup
Using this command, an authoritative response is implied by the absence of non-authoritative response in the reply.
nslookup
DNS ___ incorporate type information that identifies the kind of RR being carried and otherwise describes the record's contents and validity.
packet structures
This record stores IP address-to-domain name translation data and supports the operation known as a reverse DNS lookup.
pointer
Server where the zone data on a secondary server always originates from.
primary
Type of query issued from the client side by most DNS resolvers.
recursive query
Type of query that keeps working until an answer of some kind is forthcoming.
recursive query
DNS clients rely on this software component to interact with an available DNS server for name resolution services.
resolver
Is used when a TCP/IP client sends a name query to a DNS server, that client obtains the address for the DNS server it queries from its TCP/IP configuration data.
resolver
These issue recursive queries that go to a designated DNS server, which either answers that query itself or queries other name servers until an answer is forthcoming.
resolvers
DNS databases consists of a collection of ___, in which such databases consist of a collection of zone files that represents a static snapshot of those databases.
resource records
It is necessary to add ______ for the DNS root servers to the cache of any DNS server during initial configuration and setup.
resource records
Where data associated with domain names, address records, and other specific data of interest to the DNS stored on a DNS server is kept.
resource records
Ordinary DNS servers will accept either authoritative or nonauthoritative replies to their queries, but ___ DNS servers accept only authoritative replies to ensure the validity of the data they supply to DNS servers lower in the domain name hierarchy.
root
