🌐 DNS Lookup

A Record (Address): • Maps domain name to IPv4 address • Example: example.com → 93.184.216.34 AAAA Record (IPv6 Address): • Maps domain name to IPv6 address • Example: example.com → 2606:2800:220:1:248:1893:25c8:1946 CNAME Record (Canonical Name): • Maps alias domain to canonical domain • Example: www.example.com → example.com MX Record (Mail Exchange): • Specifies mail servers for domain • Includes priority values (lower = higher priority) • Example: example.com → 10 mail.example.com NS Record (Name Server): • Specifies authoritative name servers for domain • Example: example.com → ns1.example.com TXT Record (Text): • Contains arbitrary text data • Used for SPF, DKIM, domain verification • Example: "v=spf1 include:_spf.google.com ~all" SOA Record (Start of Authority): • Contains administrative information about domain • Includes primary name server, admin email, serial number PTR Record (Pointer): • Used for reverse DNS lookups • Maps IP address to domain name SRV Record (Service): • Specifies location of services • Format: priority weight port target CAA Record (Certificate Authority Authorization): • Specifies which CAs can issue certificates • Example: 0 issue "letsencrypt.org"

Common DNS Commands: • nslookup domain.com - Basic DNS lookup • nslookup -type=MX domain.com - Query specific record type • dig domain.com - Detailed DNS information • dig @8.8.8.8 domain.com - Query specific DNS server • dig domain.com ANY - Query all record types • dig -x 8.8.8.8 - Reverse DNS lookup • host domain.com - Simple DNS lookup • host -t MX domain.com - Query specific record type Windows Commands: • nslookup domain.com • nslookup -type=MX domain.com • ping domain.com (shows A record resolution)