Sure! Below is the combined cheat sheet that includes both the DNS records table and the command-line tools for querying and managing DNS.
DNS Cheat Sheet
Overview
The Domain Name System (DNS) is a hierarchical naming system used to translate human-readable domain names (e.g., <www.example.com>) into numerical IP addresses (e.g., 192.0.2.1) required for locating and identifying computer services and devices.
Common DNS Record Types
| Record Type | Purpose | Example |
|---|---|---|
| A | Maps a domain name to an IPv4 address | example.com -> 192.168.1.1 |
| AAAA | Maps a domain name to an IPv6 address | example.com -> 2001:db8::1 |
| CNAME | Alias one domain name to another | <www.example.com> -> example.com |
| MX | Specifies mail servers for the domain | example.com -> mail.example.com (Priority: 10) |
| TXT | Holds text information for various purposes | example.com -> “v=spf1 include:_spf.example.com ~all” |
| NS | Indicates the authoritative servers for the domain | example.com -> ns1.example.com |
| SRV | Specifies the location of services | _sip._tcp.example.com -> 5 5060 sipserver.example.com |
Common DNS Command-Line Tools
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nslookup: Utility for querying the DNS.-
Basic Query:
nslookup example.com -
Query a Specific Record Type (e.g., MX):
nslookup -query=MX example.com -
Use a Specific DNS Server:
nslookup example.com 8.8.8.8
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dig(Domain Information Groper): Advanced tool for DNS queries.-
Basic Query:
dig example.com -
Query a Specific Record Type (e.g., CNAME):
dig example.com CNAME -
Query with Detailed Output:
dig +short example.com -
Query a Specific DNS Server:
dig @8.8.8.8 example.com
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host: Simple utility for DNS lookups.-
Basic Query:
host example.com -
Query a Specific Record Type (e.g., A):
host -t A example.com -
Query a Specific Record Type (e.g., MX):
host -t MX example.com
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whois: Retrieves ownership and registration information for a domain.-
Basic Query:
whois example.com
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ping: Resolves a hostname to an IP address.-
Basic Ping Command:
ping example.com
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traceroute: Shows the path packets take to reach a domain.-
Basic Command:
traceroute example.com
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digfor DNSSEC (if enabled):-
Query a DNSKEY Record:
dig example.com DNSKEY -
Query a DS Record:
dig example.com DS
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Summary
Understanding both DNS record types and common command-line tools is essential for effective domain management and troubleshooting DNS-related issues. These commands will help you query and verify DNS configurations efficiently.