When your logged in to one node of Juniper cluster which has multiple nodes since its a HA Cluster. Below prompt show shell connection to node0.
To move to the another node let say node0 to node1, you just need this command below.
— JUNOS 11.4R10.3 built 2013-11-15 06:56:20 UTC
{primary:node0}
root@FIREWALL-PRI-SRX240>
root@FIREWALL-PRI-SRX240> request routing-engine login node 1
€
— JUNOS 11.4R10.3 built 2013-11-15 06:56:20 UTC
{secondary:node1}
root@FIREWALL-PRI-SRX240>
As you can see, the shell now indicates that the prompt is now om node1 (which is the secondary).