Determining the displayed FQDN

You can configure a preferred method of determining the fully qualified domain name (FQDN) for each discovered system.

For a Level 1 discovery, the FQDN is the result of a reverse lookup of the IP address. This lookup uses the resolver library provided by the operating system and it uses any configuration provided there. For example, if, at the operating system level, the host file is preferred over DNS, information in the hosts file is considered first.

For a Level 2 discovery, TADDM performs a reverse lookup of all discovered IP addresses using the resolver library provided by the operating system. Again, the operating system configuration dictates from where the reverse lookup gets information. If DNS is not configured, or the DNS returns unwanted FQDNs, you can use the hosts file to override it.

After the discovered IP addresses have been looked up, an attempt is made to match an FQDN to the computer system. There are a number of different ways to get an FQDN and each method is attempted, in a predefined order, until a valid FQDN is found. You can modify the order so that your preferred method has a higher priority. The following methods are available:
Method 1
TADDM selects the FQDN of an IP interface where the host portion of the FQDN matches the host name of the discovered system. If there are multiple matches, the selected FQDN depends on the priority of the domain name as defined in the property: com.collation.platform.os.FqdnPriorities. This property lists the domain names in order of priority. To prioritize the domains, enter the name of the domains as a comma-separated list on one line: 
com.collation.platform.os.FqdnPriorities=domain1.company.com,
domain2.company.com,domain3.company.com

The FQDN with the highest priority for its domain is returned as the FQDN. This method uses information that is discovered about FQDNs of interfaces and computer system names.

If the priorities are not defined, TADDM goes through all of the IP interfaces. TADDM checks if the FQDN associated with a given IP interface equals the name of the computer system or if the host name portion of this FQDN equals the name of the computer system. The FQDN first matching the criteria is returned as the FQDN.

For example, a computer system named myname has two interfaces with the following FQDNs:
  • interface #1 myname.domain1.com
  • interface #2 myname.domain2.com
If the com.collation.platform.os.FqdnPriorities is not defined then the first match is returned as the FQDN name. Both names have the host portion of the FQDN matching the host name of the discovered system but the FQDN returned is myname.domain1.com. To prioritize which name is selected, use the property com.collation.platform.os.FqdnPriorities. For example, if the com.collation.platform.os.FqdnPriorities entry contains the following information:
com.collation.platform.os.FqdnPriorities=domain2.com,domain1.com
In this case, the FQDN returned is myname.domain2.com because this name has a higher priority.
Method 2
The property com.collation.platform.os.command.fqdn specifies an external command on the TADDM server that is used to do the reverse lookup. The following examples show how to use this property, enter the property on one line:
com.collation.platform.os.command.fqdn=nslookup $1 
| grep Name | awk '{print $2}'
com.collation.platform.os.command.fqdn.AIX=nslookup $1 
| grep Name | awk '{print $2}'
com.collation.platform.os.command.fqdn.Linux=nslookup $1 
| grep Name | awk '{print $2}'
com.collation.platform.os.command.fqdn.SunOS=nslookup $1 
| grep Name | awk '{print $2}'
com.collation.platform.os.command.fqdn.Windows=nslookup $1
Method 3
The property com.collation.platform.os.command.hostOfHostname specifies an external command on the target system that is used to provide the FQDN. This property can be scoped to the operating system type by appending “.AIX”, “.Linux”,”.SunOS” or “.Windows“. The following example shows how to use this property on a Linux system. Enter the property on one line: 
com.collation.platform.os.command.hostOfHostname.Linux=host `hostname` 
| awk {'print $1'}
Method 4
The FQDN of the primary interface is used. The primary IP interface is specified as the lowest IP value where the IP values are sorted in ascending order.
Method 5
The IP address of the primary interface is used.
Method 6
The name of the computer system is used.
Method 7
Set to the session context IP.
Method 8
Set FQDN for CS as FQDN for the session IP.

You can define the order in which these methods are attempted by setting the com.collation.platform.os.fqdnSearchOrder property. The value of this property is a comma-separated list of the numbers of the methods. The default value is 1,2,3,4,5,6,7,8. In this case, TADDM first tries to use method 1. If it does not return a valid FQDN, it tries method 2, and so on, until it gets a valid FQDN and stops. A valid FQDN is a fully qualified domain name that conforms to the rules specified in RFC 1035.

This solution is also applicable for computer systems that are discovered through the use of SNMP sensors. You can define which solutions have a higher priority and therefore can be used to find an FQDN more quickly.

In all cases, properly configured DNS is the preferred way of setting host names. If DNS cannot be used, use the hosts file. The use of DNS or the hosts file are the standard ways of providing name resolution for IP addresses. TADDM provides ways to override these methods, but because any other methods are unique to TADDM, they might lead to names that are inconsistent with names in other management systems.