Mod 08: Configuring and Managing Network Services

DHCP failover

A configuration that provides fault tolerance for IPv4 scopes on two DHCP servers.

DHCP Server

A server that dynamically assigns an IP address and other network configuration parameters to each device on a network so they can communicate with other IP networks. DHCP is an enhancement of an older protocol called BOOTP.

DNS Server

A server that maintains a directory of domain names and translates them to Internet Protocol (IP) addresses. This is necessary because, although domain names are easy for people to remember, computers or machines access websites based on IP addresses.

WINS Server

A server used to resolve DNS names.

IP Address Management (IPAM)

A software product that provides for centralized management of servers.

replication partner

A WINS server deployed on the network that is configured to share its NetBIOS name records.

resolver

A client computer.

root hints

DNS data stored in a DNS server. The root hints file provides a list of preliminary resource records that can be used by the DNS service to locate other DNS servers that are authoritative for the root of the DNS domain namespace tree.

Active Directory-integrated primary DNS server

A DNS server that is also a domain controller, where zone files can be stored in the Active Directory database and replicated to other domain controllers that are also configured as DNS servers.

iterative query

A DNS query where the client communicates directly with each DNS server involved in the lookup. This is in contrast to a recursive query lookup, where one DNS server communicates with several other DNS servers to hunt down an IP address and return it to the client.

authoritative

A DNS server that contains resource records for one or more zones is said to be authoritative for those zones.

caching-only DNS server

A DNS server that does not contain any zones, but instead relays forward lookups and caches the results.

default forwarder

A DNS server that forwards requests it cannot resolve to other DNS servers instead of using root hints to perform recursive queries.

hosts file

A file used to map hostnames (in other words, domains) to IP addresses.

debug logging

A logging option that obtains more detailed information if the information in the DNS Server log is not sufficient to locate a solution to a problem.

recursive query

A lookup where one DNS server communicates with several other DNS servers to hunt down an IP address and return it to the client. This is in contrast to an iterative DNS query, where the client communicates directly with each DNS server involved in the lookup.

Network Time Protocol (NTP)

A networking protocol for clock synchronization between computer systems over packet-switched, variable-latency data networks. In operation since before 1985, NTP is one of the oldest Internet protocols in current use.

NetBIOS name record

A record containing a NetBIOS name, which is a 16-byte name for a networking service or function on a machine running Microsoft Windows Server. NetBIOS names are a more friendly way of identifying computers on a network than network numbers and are used by NetBIOS-enabled services and applications.

stub DNS server

A stub DNS server forwards requests for a target organization's zone directly to a DNS server in the target organization.

round robin

A technique of load distribution, load balancing, or fault-tolerance provisioning of multiple, redundant Internet Protocol service hosts, e.g., Web server and FTP servers, by managing the Domain Name System's (DNS's) responses to address requests from client computers according to an appropriate statistical model.

scope

A way to organize the settings for each IPv4 and IPv6 network so that the DHCP tool can provide IP configurations for them.

MAC address filtering

Adds an extra layer of security that checks the device's MAC address against a list of agreed addresses. If the client's address matches one on the router's list, access is granted, otherwise, it does not join the network.

reservation

Allows an administrator to provide the same IP address each time a DHCPDISCOVER packet is received from a DHCP client that has a certain MAC address.

secondary DNS server

An additional DNS server in a DNS zone that contains a read-only copy of the zone file from the primary DNS server that can be used to respond to DNS lookup requests.

zone

Any distinct, contiguous portion of the domain name space in the Domain Name System (DNS) for which administrative responsibility has been delegated to a single manager. The domain name space of the Internet is organized into a hierarchical layout of subdomains below the DNS root domain.

DHCP relay agent

Any host that forwards DHCP packets between clients and servers. Relay agents are used to forward requests and replies between clients and servers when they are not on the same physical subnet.

reverse lookup

Configuring the DNS to resolve IP addresses to FQDNs. Reverse DNS lookup is using an Internet IP address to find a domain name.

forward lookup

Forward DNS lookup is using an Internet domain name to find an IP address.

netmask ordering

If enabled on a DNS server, the DNS server will look at the IP address of the client that is performing the DNS query. When multiple DNS records exist on the same host name, the DNS server will respond back with a host name that is in the same network as the client when possible. In some cases there may be multiple DNS records in the same network as the client. If round robin is also enabled, the DNS records that are on that network will be cycled through.

Windows Internet Name Service (WINS)

Microsoft's implementation of NetBIOS Name Service. It is a name server and service for NetBIOS computer names. Effectively, WINS is to NetBIOS names what the DNS is to domain names: a central mapping of host names to network addresses.

DHCP policy

Provides a specific IP range or DHCP options for DHCP clients based on criteria in the DHCPDISCOVER packet.

resource record

Record that contains the FQDN and IP information for computers in a zone.

stale resource records

Records that are no longer valid but have accumulated in zone data over time.

scavenging

Removing stale resource records.

zone file

Stores resource records for the zone.

DHCP option

Tagged data items that provide information to a DHCP client. The options are sent in a variable-length field at the end of a DHCP message.

Time To Live (TTL)

The amount of time that a computer is able to cache the result of a lookup.

dynamic DNS (DDNS)

The dynamic update feature of the DNS.

primary DNS server

The first DNS server in a zone.

DNS Server log

The primary log where the DNS records information.

zone transfer

The process of copying newly added resource records from the primary DNS server to a secondary DNS server.