Error backup if client to other vlan

HI

ihave problem with some backup that vm or server ph is on other vlan network agent and add client dp is oh but when start backup show this massage :

[Major] From: BSM@srv2077.123.net "A_TEST1"  Time: 2014/09/22 8:39:45 AM

[61:3003]   Lost connection to VBDA named "C:"
 on host test1.123.net.
 Ipc subsystem reports: "IPC Invalid Packet Size"

[Major] From: BSM@srv2077.123.net "A_TEST1"  Time: 2014/09/22 8:39:50 AM
[61:3003]   Lost connection to VBDA named "C:"
 on host test1.123.net.
 Ipc subsystem reports: "IPC Invalid Packet Size"

thanks