Pular para o conteúdo
1337skills 1337skills - Folhas de Dicas

Dig - Pesquisa e Solução de Problemas de DNS

✅ Todos os comandos dig foram copiados para a área de transferência!

Dig (Domain Information Groper) é uma poderosa ferramenta de linha de comando para pesquisa e solução de problemas de DNS. É mais flexível e fornece uma saída mais detalhada do que nslookup, tornando-se a ferramenta preferida para diagnósticos e investigação de DNS.

Uso Básico

Pesquisa DNS Simples

Especificando Tipos de Registros

Especificação de Servidor DNS

Usando Diferentes Servidores DNS

Servidores DNS IPv6

Opções de Controle de Saída

Formatando Saída

Rastreamento Detalhado

Opções Avançadas de Consulta

Comportamento de Consulta

Opções DNSSEC

Pesquisas DNS Reverso

Consultas de Registro PTR

Consultas em Lote

Múltiplos Domínios

Consultas com Script

Registros DNS Especializados

Registros Relacionados a E-mail

Registros de Descoberta de Serviço

Registros de Segurança

Solucionando Problemas de DNS

Diagnósticos Comuns

Diagnóstico de Erros

Análise de Caminho de Rede

Teste de Desempenho

Tempo de Consulta

Teste de Carga

Would you like me to continue with specific translations for the sections that are currently empty?```bash

Basic A record lookup

dig google.com dig example.com dig github.com

Lookup with specific DNS server

dig @8.8.8.8 google.com dig @1.1.1.1 google.com dig @208.67.222.222 google.com

Short output (just the answer)

dig +short google.com dig +short @8.8.8.8 google.com


### Specifying Record Types
```bash
# A record (IPv4 address)
dig google.com A
dig +short google.com A

# AAAA record (IPv6 address)
dig google.com AAAA
dig +short google.com AAAA

# MX record (mail exchange)
dig google.com MX
dig +short google.com MX

# NS record (name servers)
dig google.com NS
dig +short google.com NS

# TXT record (text records)
dig google.com TXT
dig +short google.com TXT

# CNAME record (canonical name)
dig www.google.com CNAME
dig +short www.google.com CNAME

# SOA record (start of authority)
dig google.com SOA
dig +short google.com SOA

# PTR record (reverse DNS)
dig google.com PTR

# ANY record (all available records)
dig google.com ANY

DNS Server Specification

Using Different DNS Servers

# Google DNS
dig @8.8.8.8 google.com
dig @8.8.4.4 google.com

# Cloudflare DNS
dig @1.1.1.1 google.com
dig @1.0.0.1 google.com

# OpenDNS
dig @208.67.222.222 google.com
dig @208.67.220.220 google.com

# Quad9 DNS
dig @9.9.9.9 google.com
dig @149.112.112.112 google.com

# Local DNS server
dig @192.168.1.1 google.com

# Multiple servers (dig will try each)
dig @8.8.8.8 @1.1.1.1 google.com

IPv6 DNS Servers

# Google IPv6 DNS
dig @2001:4860:4860::8888 google.com
dig @2001:4860:4860::8844 google.com

# Cloudflare IPv6 DNS
dig @2606:4700:4700::1111 google.com
dig @2606:4700:4700::1001 google.com

# OpenDNS IPv6
dig @2620:119:35::35 google.com
dig @2620:119:53::53 google.com

Output Control Options

Formatting Output

# Short output (answer only)
dig +short google.com

# Show only answer section
dig +noall +answer google.com

# Show only authority section
dig +noall +authority google.com

# Show only additional section
dig +noall +additional google.com

# Show question and answer
dig +noall +question +answer google.com

# Multiline output
dig +multiline google.com

# No comments
dig +nocomments google.com

# No statistics
dig +nostats google.com

# No question section
dig +noquestion google.com

# No answer section
dig +noanswer google.com

# No authority section
dig +noauthority google.com

# No additional section
dig +noadditional google.com

Detailed Tracing

# Trace the full DNS resolution path
dig +trace google.com

# Trace with short output
dig +trace +short google.com

# Trace specific record type
dig +trace google.com MX

# Show all name servers for domain
dig +nssearch google.com

# Show all name servers with details
dig +nssearch +noall +answer google.com

Advanced Query Options

Query Behavior

# Disable recursion
dig +norecurse google.com

# Use TCP instead of UDP
dig +tcp google.com
dig +vc google.com

# Force UDP (default)
dig +notcp google.com

# Set query timeout
dig +time=5 google.com
dig +time=10 google.com

# Set number of tries
dig +tries=3 google.com

# Set number of retries
dig +retry=2 google.com

# Set UDP buffer size
dig +bufsize=512 google.com
dig +bufsize=4096 google.com

# Enable EDNS
dig +edns=0 google.com

# Ignore truncation
dig +ignore google.com

# Fail on truncation
dig +fail google.com

DNSSEC Options

# Request DNSSEC records
dig +dnssec google.com

# Check DNSSEC validation
dig +cd google.com

# Request authentic data
dig +ad google.com

# Show DNSSEC chain
dig +trace +dnssec google.com

# Validate DNSSEC signatures
dig +sigchase google.com

# Show DNSKEY records
dig google.com DNSKEY

# Show DS records
dig google.com DS

# Show RRSIG records
dig google.com RRSIG

Reverse DNS Lookups

PTR Record Queries

# Reverse lookup using -x flag
dig -x 8.8.8.8
dig -x 1.1.1.1
dig -x 192.168.1.1

# Manual PTR lookup
dig 8.8.8.8.in-addr.arpa PTR
dig 1.1.1.1.in-addr.arpa PTR

# IPv6 reverse lookup
dig -x 2001:4860:4860::8888

# Short reverse lookup
dig +short -x 8.8.8.8

# Reverse lookup with specific server
dig @8.8.8.8 -x 1.1.1.1

Batch Queries

Multiple Domains

# Query multiple domains
dig google.com yahoo.com microsoft.com

# Query from file
echo -e "google.com\nyahoo.com\nmicrosoft.com" > domains.txt
dig -f domains.txt

# Query different record types for same domain
dig google.com A MX NS TXT

# Batch with specific server
dig @8.8.8.8 -f domains.txt

Scripted Queries

# Loop through domains
for domain in google.com yahoo.com microsoft.com; do
    echo "=== $domain ==="
    dig +short $domain
done

# Check multiple record types
for type in A AAAA MX NS TXT; do
    echo "=== $type records for google.com ==="
    dig +short google.com $type
done

Specialized DNS Records

# MX records (mail exchange)
dig google.com MX
dig +short google.com MX

# SPF records (in TXT)
dig google.com TXT|grep "v=spf1"
dig _spf.google.com TXT

# DMARC records
dig _dmarc.google.com TXT

# DKIM records
dig selector1._domainkey.google.com TXT

# Mail server A records
dig gmail-smtp-in.l.google.com A

Service Discovery Records

# SRV records (service records)
dig _sip._tcp.example.com SRV
dig _xmpp-server._tcp.example.com SRV
dig _minecraft._tcp.example.com SRV

# CAA records (certificate authority authorization)
dig google.com CAA

# NAPTR records (naming authority pointer)
dig example.com NAPTR

# LOC records (location)
dig example.com LOC

Security Records

# TLSA records (DNS-based authentication)
dig _443._tcp.example.com TLSA
dig _25._tcp.mail.example.com TLSA

# SSHFP records (SSH fingerprints)
dig example.com SSHFP

# CERT records (certificates)
dig example.com CERT

Troubleshooting DNS Issues

Common Diagnostics

# Check if domain exists
dig +short google.com

# Check authoritative name servers
dig +short google.com NS

# Query authoritative server directly
dig @ns1.google.com google.com

# Check SOA record for domain info
dig google.com SOA

# Trace full resolution path
dig +trace google.com

# Check for DNS propagation
dig @8.8.8.8 example.com
dig @1.1.1.1 example.com
dig @208.67.222.222 example.com

Error Diagnosis

# Check for NXDOMAIN (domain doesn't exist)
dig nonexistent.google.com

# Check for SERVFAIL
dig +trace problematic.domain.com

# Check for timeout issues
dig +time=1 +tries=1 slow.server.com

# Check for truncation
dig +bufsize=512 large.response.com

# Verify DNSSEC
dig +dnssec +cd google.com

Network Path Analysis

# Test different DNS servers
for server in 8.8.8.8 1.1.1.1 208.67.222.222; do
    echo "Testing $server:"
    dig @$server +time=3 google.com|grep "Query time"
done

# Check local vs remote DNS
dig @127.0.0.1 google.com
dig @8.8.8.8 google.com

# Test UDP vs TCP
dig +notcp google.com
dig +tcp google.com

Performance Testing

Query Timing

# Show query time
dig google.com|grep "Query time"

# Multiple queries for average
for i in \\\\{1..5\\\\}; do
    dig google.com|grep "Query time"
done

# Time multiple servers
for server in 8.8.8.8 1.1.1.1 208.67.222.222; do
    echo "Server: $server"
    dig @$server google.com|grep "Query time"
done

Load Testing

# Rapid queries (be careful with rate limiting)
for i in \\\\{1..10\\\\}; do
    dig +short google.com &
done
wait

# Measure DNS cache performance
dig google.com  # First query (cache miss)
dig google.com  # Second query (cache hit)
```## Configuração e Personalização
```bash
# Create ~/.digrc for default options
echo "+short" > ~/.digrc
echo "+time=5" >> ~/.digrc
echo "+tries=2" >> ~/.digrc

# Override config file
dig +noconfig google.com
```### Variáveis de Ambiente
```bash
# Set default options
export DIG_OPTIONS="+short +time=5"
dig google.com

# Set default server
export DIG_SERVER="8.8.8.8"
dig google.com
```## Integração com Outras Ferramentas

### Combinando com Outros Comandos
```bash
# Extract IP addresses
dig +short google.com|grep -E '^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+

### Scripting Examples
```bash
#!/bin/bash
# Script de verificação de saúde de DNS

DOMAIN="example.com"
SERVERS=("8.8.8.8" "1.1.1.1" "208.67.222.222")

echo "Verificação de Saúde de DNS para $DOMAIN"
echo "================================"

for server in "$\{SERVERS[@]\}"; do
    echo "Testando servidor: $server"

    # Testar registro A
    A_RECORD=$(dig @$server +short $DOMAIN A)
    if [ -n "$A_RECORD" ]; then
        echo "  Registro A: $A_RECORD"
    else
        echo "  Registro A: FALHOU"
    fi

    # Testar tempo de consulta
    QUERY_TIME=$(dig @$server $DOMAIN|grep "Query time"|awk '\{print $4\}')
    echo "  Tempo de Consulta: $\{QUERY_TIME\}ms"

    echo ""
done

Cross-Platform Considerations

Linux

# Instalar dig (geralmente parte de bind-utils ou dnsutils)
sudo apt install dnsutils          # Ubuntu/Debian
sudo yum install bind-utils         # RHEL/CentOS
sudo dnf install bind-utils         # Fedora

# Ferramentas alternativas
host google.com                     # Consulta DNS simples
nslookup google.com                 # Consulta DNS interativa

macOS

# dig é pré-instalado no macOS
dig google.com

# Instalar via Homebrew para a versão mais recente
brew install bind

# Ferramentas alternativas
host google.com
nslookup google.com

Windows

# dig não está incluído por padrão
# Baixar do ISC BIND ou usar alternativas

# Alternativas do Windows
nslookup google.com
Resolve-DnsName google.com          # PowerShell

Best Practices

Security Considerations

  • Use trusted DNS servers for sensitive queries
  • Be aware that DNS queries can be logged
  • Consider using DNS over HTTPS (DoH) or DNS over TLS (DoT)
  • Validate DNSSEC when security is critical

Performance Tips

  • Use +short for scripting to reduce output parsing
  • Set appropriate timeouts for your network
  • Use local DNS caching when possible
  • Consider the impact of DNS queries on rate limiting

Troubleshooting Methodology

  1. Start with basic queries to verify connectivity
  2. Use +trace to understand the resolution path
  3. Test multiple DNS servers to isolate issues
  4. Check both forward and reverse DNS
  5. Verify DNSSEC when applicable

Monitoring and Automation

  • Log DNS query times for performance monitoring
  • Set up alerts for DNS resolution failures
  • Use batch queries for efficiency
  • Implement proper error handling in scripts

Dig is an essential tool for DNS troubleshooting and investigation. Its flexibility and detailed output make it invaluable for network administrators, security professionals, and developers working with DNS-dependent applications.

Get all A records and ping them

dig +short google.com A|while read ip; do echo “Pinging $ip” ping -c 1 $ip done

Check if domain resolves to specific IP

if dig +short google.com|grep -q “172.217.”; then echo “Domain resolves to Google IP range” fi

Compare DNS responses

diff <(dig @8.8.8.8 +short google.com) <(dig @1.1.1.1 +short google.com)

__CODE_BLOCK_22__

## Considerações Multiplataforma

### Linux
__CODE_BLOCK_23__

### macOS
__CODE_BLOCK_24__

### Windows
__CODE_BLOCK_25__

## Melhores Práticas

### Considerações de Segurança
- Use servidores DNS confiáveis para consultas sensíveis
- Esteja ciente de que consultas DNS podem ser registradas
- Considere usar DNS sobre HTTPS (DoH) ou DNS sobre TLS (DoT)
- Valide DNSSEC quando a segurança for crítica

### Dicas de Desempenho
- Use +short para scripts para reduzir o processamento de saída
- Defina timeouts apropriados para sua rede
- Use cache de DNS local quando possível
- Considere o impacto de consultas DNS em limitação de taxa

### Metodologia de Solução de Problemas