Dear Reader,
In some system landscapes, you may encounter a scenario where a single IP address serves as both the primary (physical) and secondary (virtual) IP. In other words, both the virtual and physical hostnames are mapped to the same IP address.
During the Software Provisioning Manager (SWPM) execution, this setup may lead to a hostname resolution error that prevents you from proceeding with the installation.
Example Error Log from SWPM
This computer’s host name is ‘<Virtual-Hostname>’ but a reverse lookup returned ‘<Physical-Hostname>’. This will lead to problems later on when starting the Web Application Server. SOLUTION: Insert a line: ‘<IP-address> <Virtual-Hostname>’ into the host file ‘/etc/hosts’, and then continue with the installation.
Root Cause
SWPM performs a reverse DNS lookup during the installation process. If both virtual and physical hostnames are associated with the same IP address, the nslookup may return the physical hostname instead of the expected virtual hostname, triggering the above error.
Solution
As suggested in the error message, ensure that the virtual hostname entry is correctly maintained in the /etc/hosts file.
If both the virtual and physical hostnames are defined for the same IP address, the order of entries in the /etc/hosts file becomes crucial.
Make sure that the virtual hostname entry appears before the physical hostname entry, as shown below:
<IP-address> <Virtual-Hostname> <Virtual-Hostname.domain>
<IP-address> <Physical-Hostname> <Physical-Hostname.domain>
This simple adjustment ensures that the reverse lookup resolves the correct virtual hostname, allowing the SWPM process to continue without errors.
Thank you for reading. Please feel free to share your thoughts.
Dear Reader,In some system landscapes, you may encounter a scenario where a single IP address serves as both the primary (physical) and secondary (virtual) IP. In other words, both the virtual and physical hostnames are mapped to the same IP address.During the Software Provisioning Manager (SWPM) execution, this setup may lead to a hostname resolution error that prevents you from proceeding with the installation.Example Error Log from SWPMThis computer’s host name is ‘<Virtual-Hostname>’ but a reverse lookup returned ‘<Physical-Hostname>’. This will lead to problems later on when starting the Web Application Server. SOLUTION: Insert a line: ‘<IP-address> <Virtual-Hostname>’ into the host file ‘/etc/hosts’, and then continue with the installation.Root CauseSWPM performs a reverse DNS lookup during the installation process. If both virtual and physical hostnames are associated with the same IP address, the nslookup may return the physical hostname instead of the expected virtual hostname, triggering the above error.SolutionAs suggested in the error message, ensure that the virtual hostname entry is correctly maintained in the /etc/hosts file.If both the virtual and physical hostnames are defined for the same IP address, the order of entries in the /etc/hosts file becomes crucial.Make sure that the virtual hostname entry appears before the physical hostname entry, as shown below:<IP-address> <Virtual-Hostname> <Virtual-Hostname.domain><IP-address> <Physical-Hostname> <Physical-Hostname.domain>This simple adjustment ensures that the reverse lookup resolves the correct virtual hostname, allowing the SWPM process to continue without errors.Thank you for reading. Please feel free to share your thoughts. Read More Technology Blog Posts by SAP articles
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