how to integrate Juno space with SRX cluster

to integrate SRX cluster to Juno space is not straight forward. you have a couple of solutions

1. bidirectional NAT on backup router is best solution, source nat your Juno space server to an ip in same subnet as both Fxp0.0 destination NAT two ip to both fxp0.0 as well. ( yourJuno space is isolate with cluster management IPs)

2. backup route
never use backup route 0.0.0.0/0, please use specified ip as following, please remember, backup-router is only working for standby node, not working with active node, for active node you can use static route, but you might have problem if your cluster works as your main router in your network, all traffic to Juno space server will be affect via this cluster. you might need use static route base on source IP to fix the connection between other devices to Juno space.

groups {
    node0 {
         ...
            backup-router 192.168.1.254 destination 172.16.1.1/32;
            ...
    }
    node1 {
            ...
            backup-router 192.168.1.254 destination 172.16.1.1/32;
            ...
    }

routing-options {
    static {
        route 172.16.1.1/24 {
            next-hop 192.168.1.254;
            retain;
            no-readvertise;
        }
        route 172.16.1.1/24 {
            next-hop 192.168.1.254;;
            retain;
            no-readvertise;
        }
    }
}