Hi Frank,
Thru Rest we have only one link to fetch the landscape details
http://localhost:8080/spectrum/restful/landscapes
Which will give below info when Primary is on
=================================
<?xml version="1.0" encoding="UTF-8" standalone="true"?>
-<landscape-response total-landscapes="1" xmlns="http://www.ca.com/spectrum/restful/schema/response">
-<landscape>
<id>0x100000</id>
<name>NAM-SS</name>
<isPrimary>true</isPrimary>
<spectrumVersion>10.2.0.000</spectrumVersion>
</landscape>
</landscape-response>
Below info when Secondary is on
============================
<?xml version="1.0" encoding="UTF-8" standalone="true"?>
-<landscape-response total-landscapes="1" xmlns="http://www.ca.com/spectrum/restful/schema/response">
-<landscape>
<id>0x100000</id>
<name>NAM-SS</name>
<isPrimary>false</isPrimary>
<spectrumVersion>10.2.0.000</spectrumVersion>
</landscape>
</landscape-response>
So as per my knowledge you will not be able to get the secondary hostname or ip through rest api
Regards
Sunny