Hello ,
Both Nodes on SRX cluster can be added to Junos Space using the FXP0 IP which is different in each node . If you are unable to connect the secondary node , make sure you can access the secondary FXP IP from Space . If not , make sure you have backup router configuration :
2- Should I use master IP of cluster to add in Space?
> As mentioned SRX connects using the FXP IP which is different for node0 and 1 . So make sure you add them using the FXP IP and not the master one .