Why is the DNS server not responding?

Related questions

1. What is the purpose of reverse DNS?
2. How long is DNS cache stored?
3. How do records work?
4. What is the best TTL value?
5. What do DNS records do?
6. How does reverse DNS work?
7. Why PTR record is created in DNS?
8. How long do DNS TXT records take to propagate?
9. What is an A record in DNS?
10. What type of record is used for DNS reverse lookup?

Tags

1. #responding
2. #problem
3. #server
4. #right
5. #google
6. #error
7. #changes
8. #connections
9. #helps
10. #change
11. #internet
12. #check
13. #start
14. #click
15. #select
16. #network
17. #settings