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Displays the status of the DNS resolver. If DNS is not enabled, dns info will display a message to that effect. Otherwise dns info displays a list of all DNS servers configured in the resolv.conf file, whether the appliance believes the server to be operational, when the server was last polled, the average time in milliseconds for a DNS query, how many DNS queries were made, and how many queries resulted in errors. Following the list of servers is the appliance's default domain (that is, a node named toaster with a default domain of mycompany.com thinks its fully qualified name is toaster.mycompany.com) and a list of domains that are appended to unqualified names during lookup. Here is a sample output:
DNS is enabled DNS caching is enabled 5 cache hits 4 cache misses 4 cache entries 0 expired entries 0 cache replacements IP Address State Last Polled Avg RTT Calls Errs ------------------------------------------------------------------------------- 172.19.2.30 UP Mon Oct 22 20:30:05 PDT 2001 2 12 0 172.19.3.32 ?? 0 0 0 Default domain: lab.mycompany.com Search domains: lab.mycompany.com mycompany.com
The table of DNS servers indicated the IP address, last known status, date of last DNS request, average round trip time (RTT) in milliseconds, number of requests, and number of errors reported per server. If a server has never been queried it will have a "??" in its status field. If the server responded to its last query it will have "UP" in in its status field, and if it never responded to the last query sent or had any other error condition it will have "DOWN" in its status field. Down servers will not be retried for 10 minutes.
The default domain listed should be the same as the value of the dns.domainname option. The search domains are the domain suffixes used to convert unqualified domain names in fully qualified domain names (FQDNs). They are read from the search directive in /etc/resolv.conf.
Removes all entries from the DNS cache. This command has no effect if the DNS cache is not enabled. All responses from a DNS server have a TTL (Time to Live) value associated with them. Cache entries will normally expire at the end of their time to live and a new value will be acquired from the DNS server. However if a DNS record changes before it has expired the DNS cache has no way of knowing that its information is up to date. In this case name resolutions on the node will incorrectly return the old record and you must flush the DNS cache to force the node to get the new DNS record. If some of your DNS records change very often you should make sure that your DNS server transmits them with a low TTL. You can also disable DNS caching on the node via the dns.cache.enable option, but this may have an adverse performance impact.
Configures the DNS resolver
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