Target node/queue unavailable in Concurrent Manager

HI,

OS : RHL 7

Apps: 12.2.5

db:     12.1.0.2

Application was working fine all of a sudden all submitted requested started showing no managers and concurrent manager status changed Target node/queue. ICM is working fine.

select NODE_NAME,NODE_MODE,STATUS from fnd_nodes;

NODE_NAME           NODE_MODE      STATUS

AUTHENTICATION      O

ffddadb                         O                          N        

ffmaddaerp                  O                          N   

select substr(node_name, 1, 20) node_name, node_mode, server_address,server_id, substr(host, 1, 15) host,

      substr(domain, 1, 20) domain, substr(support_cp, 1, 3) cp, substr(support_web, 1, 3) web,

       substr(support_admin, 1, 3) ADMIN, substr(support_forms, 1, 3) FORMS,

       substr(SUPPORT_DB, 1, 3) db, substr(VIRTUAL_IP, 1, 30) virtual_ip

       from fnd_nodes;