CST8200 - Windows Domain Administration Week 2

CST8200 - Windows Domain Administration

• Course is taught by Denis Latremouille
• Week 2 topics include Windows Server, Case Study Review, DNS Install, Configure, Manage, and DNS Demo

Introduction to Domain Name System

• DNS is used to resolve names to IP addresses and vice versa
• Computers communicate with numbers, but people prefer names
• Many other services rely on DNS for various purposes
• Authentication and certificate authorities use DNS for security
• Dynamic DNS allows computers to locate each other even with dynamic IPs

DNS Order of Operations

• When a computer needs an IP address, it first checks
  • Localhost (127.0.0.1 - 127.255.255.254)
  • DNS cache
  • HOST file
• If not found, the computer requests the information from its DNS resolver over UDP port 53
• The DNS server handles the information exchange

Introduction to Domain Name System (Continued)

• DNS is a distributed hierarchical database of computer names and IP addresses
• No single database contains all data
• Finding an address requires querying multiple DNS servers within a hierarchy

DNS Naming Hierarchy

• A visual hierarchy (tree structure) of domains
• Top-level domains (TLDs) (e.g., .com, .edu)
• Second-level domains (e.g., microsoft.com, cengage)
• Subdomains (e.g., mdsn.microsoft.com, downloads.microsoft.com)

The DNS Database

• A zone is a grouping of DNS information for one or more domains and subdomains
• Zones contain resource records with information about network resources
• Resource records are identified by codes (e.g., A, AAAA, MX, NS)
• Examples of helpful analogies and explanations are provided via Youtube links

The DNS Lookup Process

• Two types of DNS lookups: iterative and recursive
• Iterative: the server returns the best match or a referral
• Recursive: the server continues the lookup until a response is found or a "don't know" message is returned
• DNS clients maintain static DNS entries

DNS Server Roles

• Authoritative servers hold complete zone copies
• Forwarders send unresolved requests to other servers
• Conditional forwarders target requests for specific domains
• Caching-only servers cache results after recursive lookups or forwarder requests

Configuring DNS

• Three key aspects: DNS zones (forward lookup, reverse lookup), DNS resource records, DNS server settings
• Various record types (e.g., A, NS, MX, CNAME, AAAA, PTR, SRV)

Forward and Reverse Lookup Zones

• Forward lookup zones (FLZ) translate names to IP addresses (e.g., A, AAAA, MX records)
• Reverse lookup zones (RLZ) map IP addresses to names (e.g., PTR records)

Zone Type

• Primary zones are read/write masters
• Secondary zones are read-only copies
• Stub zones contain only SOA and NS records for resolving NS records

Dynamic Updates

• Dynamic updates allow client computers to register and dynamically update their resource records with a DNS server
• Configurable options for secure, nonsecure, and no dynamic updates; security is emphasized

Creating DNS Resource Records

• Resource records can be created dynamically or statically
• Dynamic records created through a resource or DHCP server
• Static records created manually by an administrator or automatically by Windows

Host (A and AAAA) Records

• Used for mapping hostnames to IP addresses

Canonical Name (CNAME) Records

• Create aliases for other domain name records within the DNS database

Pointer (PTR) Records

• Resolve IP addresses to hostnames, primarily found in reverse lookup zones

Mail Exchanger (MX) Records

• Used by mail services to identify mail servers for a domain

Service Location (SRV) Records

• Specify hostname and port numbers for specific services, crucial for Active Directory operation

Creating Dynamic DNS Records

• Dynamic DNS records are created and updated by a DHCP server when an IP address is leased or renewed
• Time-to-Live (TTL) value specifies the duration a record remains in the DNS database; expired records are removed

Configuring DNS Zones

• DNS Manager allows viewing and changing zones
• Options include status, type, replication, dynamic updates, and aging

Start of Authority (SOA) Records

• SOA records contain fundamental information identifying the server responsible for a zone, along with operational parameters

Name Server (NS) Records

• Specify authoritative servers for a zone, including FQDN and IP addresses
• Glue records contain IP addresses for name servers
• Domain name registry holds information about domain names and registrants

Creating Secondary Zones and Configuring Zone Transfers

• Secondary zones are read-only copies of primary zones
• Changes are made on the primary server and then transferred to secondary servers

Zone Transfer Settings

• Zone transfers copy zone data between DNS servers
• Configuration options include refresh intervals, DNS notify methods and the like

Configuring Traditional Forwarders

• Traditional forwarders are configured to direct queries to external DNS
• Servers are queried sequentially in order. A root server is used if queried from a forwarder does not give a result.

Configuring Conditional Forwarders

• Conditional forwarders resolve queries from locally stored records, DNS cache, conditional forwarders, traditional forwarders, and recursively using root hints.

Monitoring and Troubleshooting DNS

• Troubleshooting involves understanding where DNS is used and monitoring or using tools like DNS Manager, dcdiag, dnscmd, PowerShell, Event Viewer, dnslint, nslookup, ping, ipconfig, etc. DNS problems frequently involve performance issues.