linux_wiki:troubleshoot_dns_client_issues

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linux_wiki:troubleshoot_dns_client_issues [2016/09/29 22:52]
billdozor 		linux_wiki:troubleshoot_dns_client_issues [2019/05/25 23:50]
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-====== Troubleshoot DNS Client Issues ====== 
- 
-**General Information** 
- 
-Client perspective checking DNS configuration. 
- 
----- 
- 
-====== Troubleshooting: Unbound ====== 
- 
-View (dump) the current contents of the unbound cache 
-<code bash> 
-unbound-control dump_cache 
-</code> 
-  * This can be also redirected to a file to make edits and load back into cache 
- 
-\\ 
-Purge the cache: Single record 
-<code bash> 
-unbound-control flush myhost1.example.com 
-</code> 
- 
-\\ 
-Purge the cache: Entire Zone 
-<code bash> 
-unbound-control flush example.com 
-</code> 
- 
-\\ 
-Load cache from a file (dumped there previously) 
-<code bash> 
-unbound-control load_cache < cache.txt 
-</code> 
- 
----- 
- 
-====== Troubleshoot DNS From a Client ====== 
- 
-Check to see what DNS servers are configured 
-<code bash> 
-cat /etc/resolv.conf 
-</code> 
-  * Take note of whether the file is controlled via NetworkManager. If so, then the DNS servers are set via that service/from /etc/sysconfig/network-scripts/ 
- 
-\\ 
-Ensure a route exists to the DNS server 
-<code bash> 
-ip route sh 
-</code> 
- 
-\\ 
-Ping the DNS server 
-<code bash> 
-ping -c4 <ip-of-dns> 
-</code> 
- 
-\\ 
-Check to see if you can connect to port 53 
-<code bash> 
-telnet <ip-of-dns> 53 
- 
-OR 
- 
-nc -v -w 3 <ip-of-dns> 53 
-</code> 
- 
-\\ 
-Test a domain lookup against the DNS server directly 
-<code bash> 
-dig @<ip-of-dns> google.com 
-</code> 
- 
----- 
  
  • linux_wiki/troubleshoot_dns_client_issues.txt
  • Last modified: 2019/05/25 23:50
  • (external edit)