UCS 2.4 - Univention

4.5 Univention Directory Manager modules
The time to live specifies how long these files may be cached by other DNS servers. The preset value
is three hours.
Several servers can be entered for each service via the check box.
4.5.9.5 Reverse lookup zone
A reverse lookup zone is used to resolve IP address into host names.
’General’ tab
Subnet (*)
The IP address of the network for which the reverse lookup zone shall apply. For example, if the
network in question consisted of the IP addresses 192.168.1.0 to 192.168.1.255, 192.168.1 should
be entered.
Zone Time-to-Live (*)
The time to live specifies how long these files may be cached by other DNS servers. The preset value
is three hours.
’Start of Authority’ tab
Each DNS zone has at least one authoritative, primary name server whose information governs the
zone. Subordinate servers synchronise themselves with the authoritative server via zone transfers.
The entry which defines such a zone is called a SOA record in DNS terminology.
Contact person (*)
The e-mail address of the person responsible for administrating the zone (with a full stop at the end).
Name server (*)
The fully qualified domain name with a full stop at the end or the relative domain name of the primary
master name server.
Attention:
Only the primary master name server should be entered in this field. Further name servers can be
entered on the Name server
Serial number (*)
Other DNS servers use the serial number to recognise whether zone data have changed. The slave
name server compares the serial number of its copy with that on the master name server. If the serial
number of the slave is lower than that on the master, the slave copies the changed data.
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