Configuring Dns Settings - Cisco TelePresence Administrator's Manual

Network and system settings

Configuring DNS settings

The DNS page (System >
Configuring the system host and domain name
The System host name defines the DNS host name that this VCS is known by.
It must be unique for each peer in a cluster.
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It is used to identify the VCS on a remote log server (a default name of "TANDBERG" is used if the
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System host name is not specified).
The Domain name is used when attempting to resolve unqualified server addresses (for example
ldapserver). It is appended to the unqualified server address before the query is sent to the DNS server. If
the server address is fully qualified (for example ldapserver.mydomain.com) or is in the form of an IP
address, the domain name is not appended to the server address before querying the DNS server.
It applies to the following configuration settings in the VCS:
LDAP server
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NTP server
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External Manager server
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Remote logging server
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You are recommended to use an IP address or FQDN (Fully Qualified Domain Name) for all server
addresses.
Note that the FQDN of the VCS is the System host name plus the Domain name.
Impact on SIP messaging
The System host name and Domain name are also used to identify references to this VCS in SIP
messaging, where an endpoint has configured the VCS as its SIP proxy in the form of an FQDN (as opposed
to an IP address, which is not recommended).
In this case the VCS may, for example, reject an INVITE request if the FQDN configured on the endpoint
does not match the System host name and Domain name configured on the VCS. (Note that this check
occurs because the SIP proxy FQDN is included in the route header of the SIP request sent by the endpoint
to the VCS.)
DNS requests
By default, DNS requests use a random port from within the system's ephemeral port range.
If required, you can specify a custom port range instead by setting DNS requests port range to Use a
custom port range and then defining the DNS requests port range start and DNS requests port range
end fields. Note that setting a small source port range will increase your vulnerability to DNS spoofing
attacks.
Configuring DNS server addresses
You must specify at least one DNS server to be queried for address resolution if you want to:
Cisco VCS Administrator Guide (X8.1.1)
DNS) is used to configure the VCS's DNS servers and DNS settings.
Network settings
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