Landesk Agent unable to reply to core server after first push/installed(Only occur on PC client in different Network Subnet)

Hi All,

         I m facing problem on deployment on landesk.All the agent in PC/Client on different network subnet are unable to reply to core server after the first push.

         The agent was succesfully installed in the PC client but unable to show in the "all device list' in the core server.I try to load the inventory scan in the Client PC but it shows this error "LDISCN 32 :Failed to resolve the Host Name".This happen on all the PC in different Subnet.But for PC in the same subnet,the agent deployment was succesfully done and showed in all device list on core server.

         I had advice to the end user by opening the ports below.But they had verify and checked that they dint block any ports below.

Remote control                out    9535,9595
Inventory                            in    5007
Software distribution (push)        out    9594,9595
Software distribution (policy)        in    12175,12176
Software distribution (multicasting)    out    33354
Trusted access                           out    4444,7777
Alert management system            in    38292
Management Web services            in    80 (HTTP)
Secure Inventory/Web console        in    443 (HTTP)

         I need some help from the community.Anyone got some idea of this ???Any suggestion??

"LDISCN 32 :Failed to resolve the Host Name" Error was showed in below attached picture.

Thanks,

Roy Ooi