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This chapter explains how to configure hosts in DNS zones. Before you proceed with the concepts in this chapter, read Chapter 15, "Managing Zones," which explains how to set up the basic properties of a primary and secondary DNS server and its zones.
Managing Hosts in Zones
Adding Additional RRs for the Host
Editing Hosts
Removing Hosts
You can manage the resource records (RRs) for a host by configuring the host rather than the individual RRs. When you define a host, the DNS server automatically creates an Address (A) RR in IPv4, or an AAAA RR in IPv6, for each address you specify. If you specify one or more aliases for the host, the server also creates a Canonical Name (CNAME) RR for each alias. You can also have the server create a Pointer (PTR) RR for the host in the reverse zone for the host, if the reverse zone exists.
Step 1 From the Hosts menu, choose Hosts.
Step 2 If you have only one zone configured, the List/Add Hosts for Zone page appears and the Zones tab is inactive. If you have multiple zones configured, also click Zones, then, on the List Zones page, click the name of the zone to open the List/Add Hosts for Zone page.
Tip You can sort by hostname, IP address, IPv6 address (if appropriate), or alias by clicking the corresponding column heading on the List/Add Host for Zone page. However, for zones with a large number of hosts (more than 50,000), restrict the sort to the hostname. Sorting based on IP address or alias can take significantly longer, and could fail if you exceed the memory capacity of the CCM server.
Step 3 Enter the name of the host and its IPv4 or IPv6 address or comma-separated addresses.
Step 4 If the host has alias names, enter a comma-separated list.
Step 5 If you want to create a corresponding Pointer (PTR) RR for the host and you know that the reverse zone for the host exists, check the Create PTR Records? check box.
Step 6 Click Add Host.
Step 7 To confirm, click DNS, then Forward Zones to open the List/Add Zones page.
Step 8 Click the View icon () in the RRs column in the row of the zone name. This opens the List/Add DNS Server RRs for Zone page.
To create A RRs, alias RRs, and PTR RRs for existing reverse zones in a single operation, use zone name addHost hostname address alias for each host. To list the created zones, use zone name listHosts.
You add additional RRs for the host based on the dns edit mode you chose, either staged or synchronous. For details, see the "Adding Resource Records" section on page 16-2.
Reload the DNS server if you want these RRs to become active server RRs.
For example, to add additional CNAME RRs, add the alias hostname in the Name field of the List/Add DNS Server RRs for Zones page, choose CNAME from the Type drop-down list, add the canonical name of the host in the Data field, then click Add Resource Record. Note that the DNS specification does not allow a CNAME RR with the same name as that of another RR.
For an MX RR, add the origin hostname in the Name field; choose MX from the Type drop-down list; add the integer preference value, a space, and the domain name of the mail exchanger for the origin host in the Data field; then click Add Resource Record. These entries should appear in the list at the bottom of the page.
To create a CNAME record, use zone name addRR alias CNAME canonical for protected RRs or zone name addDNSRR alias CNAME canonical for unprotected RRs. To create an MX record, use zone name addRR hostname MX preference mxname for protected RRs or zone name addDNSRR hostname MX preference mxname for unprotected RRs.
Editing a host involves modifying its RRs.
Step 1 From the Hosts menu, choose Hosts. If you get the List Zones page, click the zone name to open the List/Add Hosts for Zone page. If there is only one zone, you immediately go to the List/Add Hosts for Zone page. Another alternative, if you are on the List Zones page, is to click the View icon () in the Hosts column in the row of the zone name to open the List/Add Hosts for Zone page.
Step 2 Click the hostname to open the Edit Host page.
Step 3 You can add additional addresses, aliases, and other RRs for the host. Click the appropriate button in each case. You can also delete an RR by clicking the Delete icon () next to its name (without a confirmation requested).
Step 4 Click Modify Host.
To edit the host, you must remove and reenter its RRs by using zone name removeRR name type data or zone name removeDNSRR name type data, then zone name addRR name ttl class type data or zone name addDNSRR name ttl type data.
Removing a host removes all A, CNAME, and PTR RRs for that host.
On the List/Add Hosts in Zone page (see the "Editing Hosts" section for the possible ways to get there), click the Delete icon () next to the host you want to remove, then confirm the deletion.
Remove the host by using zone name removeHost, then re-add it by using zone name addHost.