dns_cache

March 26, 2020 Contributors

Name

dns_cache stats, dns_cache refcnts, dns_cache submit, dns_cache lookup — manage Momentum’s DNS cache

Synopsis

dns_cache lookup { record } { type }

dns_cache refcnts

dns_cache stats

dns_cache submit { record } { type }

Description

The following commands help you to collect information on Momentum’s dns cache.

dns_cache stats shows summary statistics about the MTA’s dns cache.

dns_cache refcnts shows the count of references of each entry in the MTA’s dns cache. A cache entry can only be purged when its reference count becomes zero.

dns_cache submit record type submits a dns query, whose result will be stored in cache if not already.

dns_cache lookup record type looks up a dns query in the cache.

record type can be A, MX, PTR, X, X_AAAA, TXT, AAAA, or CNAME.

10:47:35 /tmp/2025> dns_cache lookup mail.yahoo.com A
Cached result not found, try a submit.
16:59:26 ecelerity(/tmp/2025)> dns_cache submit mail.yahoo.com A
Submitted
16:59:32 ecelerity(/tmp/2025)> dns_cache lookup mail.yahoo.com A
;; QUESTION SECTION:
;mail.yahoo.com         IN      A

;; ANSWER SECTION:
mail.yahoo.com          299     IN      A       209.73.177.115

16:59:33 ecelerity(/tmp/2025)> dns_cache stats
DNS Queries:
        TXT: 1
        PTR: 1
         MX: 1
          A: 2
  arpa IPv4: 0
  arpa IPv6: 0

DNS responses:
      Total: 5
        Bad: 0

DNS cache:
    Lookups: 14
   Hit Rate: 35.7143%

16:59:41 ecelerity(/tmp/2025)> dns_cache refcnts
[  3] mail.omniti.com [213s]
      (null)
[  3] mail.yahoo.com [282s]
      (null)
[  3] mail.yahoo.com [248s]
      (null)
[  3] mail.yahoo.com [272s]
      (null)

Note

These console commands manipulate the DNS cache . The dig, refresh domain and domain commands manipulate the route cache .