Cisco Cisco Email Security Appliance C170 Guia Do Utilizador
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Cisco AsyncOS 8.0.2 for Email User Guide
Chapter 30 Managing and Monitoring Using the CLI
Monitoring Using the CLI
Checking the DNS Status
The
dnsstatus
command returns a counter displaying statistics of DNS lookup and cache information.
For each counter, you can view the total number of events since the counter was last reset, since the last
system reboot, and over the lifetime of the system.
system reboot, and over the lifetime of the system.
lists the available counters.
19 mail.remotedomain19.com 172.16.0.20 Incoming01 1
20 mail.remotedomain20.com 172.16.0.21 Incoming01 1
Table 30-10
Data in the dnsstatus Command
Statistic
Description
DNS Requests
A top-level, non-recursive request to the system DNS cache to resolve a
domain name.
domain name.
Network Requests
A request to the network (non-local) to retrieve DNS information.
Cache Hits
A request to the DNS cache where the record was found and returned.
Cache Misses
A request to the DNS cache where the record was not found.
Cache Exceptions
A request to the DNS cache where the record was found but the domain was
unknown.
unknown.
Cache Expired
A request to the DNS cache where the record was found
in the cache, considered for use, and discarded because it was too old.
Many entries can exist in the cache even though their time to live (TTL) has
been exceeded. As long as these entries are not used, they will not be included
in the expires counter. When the cache is flushed, both valid and invalid (too
old) entries are deleted. A flush operation does not change the expires counter.
been exceeded. As long as these entries are not used, they will not be included
in the expires counter. When the cache is flushed, both valid and invalid (too
old) entries are deleted. A flush operation does not change the expires counter.