Cisco Cisco Expressway メンテナンスマニュアル
2.
In the Query type field, select the type of record you want to search for:
(for reverse lookups the Query type is ignored - the search automatically looks for PTR records)
Option
Searches for...
All
any type of record
A (IPv4 address)
a record that maps the hostname to the host's IPv4 address
AAAA (IPv6 address)
a record that maps the hostname to the host's IPv6 address
SRV (services)
SRV records (which includes those specific to H.323, SIP, Unified Communications
and TURN services, see below)
and TURN services, see below)
NAPTR (Name
authority pointer)
authority pointer)
a record that rewrites a domain name (into a URI or other domain name for
example)
example)
3.
By default the system will submit the query to all of the system's default DNS servers (System > DNS). To
query specific servers only, set Check against the following DNS servers to Custom and then select the DNS
servers you want to use.
query specific servers only, set Check against the following DNS servers to Custom and then select the DNS
servers you want to use.
4.
Click Lookup.
A separate DNS query is performed for each selected Query type. The domain that is included within the query sent
to DNS depends upon whether the supplied Host is fully qualified or not (a fully qualified host name contains at least
one "dot"):
to DNS depends upon whether the supplied Host is fully qualified or not (a fully qualified host name contains at least
one "dot"):
■
If the supplied Host is fully qualified:
—
DNS is queried first for Host
—
If the lookup for Host fails, then an additional query for Host.<system_domain> is performed (where
<system_domain> is the Domain name as configured on the DNS page)
<system_domain> is the Domain name as configured on the DNS page)
■
If the supplied Host is not fully qualified:
—
DNS is queried first for Host.<system_domain>
—
If the lookup for Host.<system_domain> fails, then an additional query for Host is performed
For SRV record type lookups, multiple DNS queries are performed. An SRV query is made for each of the following _
service._protocol combinations:
service._protocol combinations:
■
_h323ls._udp.<domain>
■
_h323rs._udp.<domain>
■
_h323cs._tcp.<domain>
■
_sips._tcp.<domain>
■
_sip._tcp.<domain>
■
_sip._udp.<domain>
■
_collab-edge._tls
■
_cisco-uds._tcp
■
_turn._udp.<domain>
■
_turn._tcp.<domain>
In each case, as for all other query types, either one or two queries may be performed for a <domain> of either Host
and/or Host.<system_domain>.
and/or Host.<system_domain>.
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Cisco Expressway Administrator Guide