Bash - DNS Commands

DNS Commands

Overview

Common DNS lookup and troubleshooting commands for network diagnostics.

Code

nslookup

# query nameserver for domain IP (bypasses cache)
nslookup [domain.com] [ns server]
 
# check local IP cache
nslookup [domain.com]
 
# see debug information (TTL, etc.)
nslookup -debug [domain.com]

Clear DNS Cache

# linux (ubuntu/debian)
sudo apt-get install nscd
sudo /etc/init.d/nscd restart
 
# alternative using systemd-resolved
sudo systemd-resolve --flush-caches
 
# windows
ipconfig /flushdns

dig Commands

# basic lookup
dig example.com
 
# query specific record type
dig example.com MX
dig example.com TXT
dig example.com A
dig example.com AAAA
 
# short output
dig +short example.com
 
# query specific nameserver
dig @8.8.8.8 example.com
 
# trace DNS resolution path
dig +trace example.com

---

Appendix

Note created on 2025-12-23 and last modified on 2025-12-23.

See Also

• Bash - Using dig for Email DNS Analysis
• Bash Code
• Linux
• Windows Subsystem for Linux (WSL)

Backlinks

---

(c) No Clocks, LLC | 2025