This is a report of the Squid DNS cache for IP address resolution.
How is it different from the ipcache?
ipcache contains data for the Hostname to IP-Number mapping, and this report does it the other way round.
FQDN Cache Statistics: FQDNcache Entries In Use: 9 FQDNcache Entries Cached: 9 FQDNcache Requests: 0 FQDNcache Hits: 0 FQDNcache Negative Hits: 0 FQDNcache Misses: 0 FQDN Cache Contents: Address Flg TTL Cnt Hostnames ::1 H -001 2 ip6-localhost ip6-loopback 127.0.0.1 H -001 2 localhost ff02::1 H -001 1 ip6-allnodes ff02::2 H -001 1 ip6-allrouters ff02::3 H -001 1 ip6-allhosts ff00::0 H -001 1 ip6-mcastprefix fe00::0 H -001 1 ip6-localnet
For the Flags (Flg) column:
C means positively cached.
N means negatively cached.
P means the request is pending being dispatched.
D means the request has been dispatched and we're waiting for an answer.
H means it is an entry loaded from the system hosts file.
L means it is a locked entry because it represents a parent or sibling.
The TTL column represents "Time To Live" (i.e., how long the cache entry is valid). This is given by the DNS system when each FQDN is retrieved. It may be negative if the entry has already expired, in which case the next request to need it will perform new DNS lookups to fetch new records.
The Cnt column is the number of hostnames which the cache has translations for.
The rest of the line lists all the hostnames that have been associated with that IP.