Phemomenon:client browses the files on the server,but as copying files from server,there is no responses for a long time, the copying fails.
NE40, NE16 are PEs,8016 transers at layer 2, NE40 established sub-interface to identify vlan,and the sub-interfac belongs to the private network VPN.
1.It is normal for client to communicate with server 1471 byte packets via non-fragement mode, while 1472 cannot.
2.The mtu configuration for ne40 to communicate with server:
vlan-type dot1q vid 50
ip binding vpn-instance xzdcn_ziyuanguanli
The problem is solved after modify mtu to 1500.
Client browses the files of server, they are all the small packets,but as copying files from server, there will be 1500-bytes packets, surpassing the MTU of NE40 and are discarded by NE40. The copying fails.