Problem with file transfer via ssh and linux clients

[hellname]

Hello,
First sorry about my english.
I have a problem with file transfer when I using softether as l2tp/ipsec vpn.

1. Info about server:
Description: Ubuntu 12.04.4 LTS
Linux xxxx 3.2.0-57-generic #87-Ubuntu SMP Tue Nov 12 21:35:10 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

2. Info about network:
ifconfig -a
br0 Link encap:Ethernet HWaddr 12:a3:e6:8d:4f:c6
inet addr:172.18.45.5 Bcast:172.18.45.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:363825049 errors:0 dropped:0 overruns:0 frame:0
TX packets:321434878 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:44647655288 (44.6 GB) TX bytes:349997123181 (349.9 GB)

br0:1 Link encap:Ethernet HWaddr 12:a3:e6:8d:4f:c6
inet addr:172.18.45.6 Bcast:172.18.45.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

br0:2 Link encap:Ethernet HWaddr 12:a3:e6:8d:4f:c6
inet addr:172.18.45.10 Bcast:172.18.45.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

br0:3 Link encap:Ethernet HWaddr 12:a3:e6:8d:4f:c6
inet addr:172.18.45.7 Bcast:172.18.45.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

br0:4 Link encap:Ethernet HWaddr 12:a3:e6:8d:4f:c6
inet addr:172.18.45.8 Bcast:172.18.45.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

eth0 Link encap:Ethernet HWaddr a4:5d:36:11:2e:95
inet addr:188.138.xx.xxx Bcast:188.138.xx.xxx Mask:255.255.255.192
UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1
RX packets:697145128 errors:0 dropped:134 overruns:0 frame:80
TX packets:778762782 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:463128545173 (463.1 GB) TX bytes:546814395660 (546.8 GB)
Interrupt:18

eth1 Link encap:Ethernet HWaddr 68:05:ca:1e:89:8d
UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1
RX packets:2489523662 errors:0 dropped:5101834 overruns:0 frame:0
TX packets:1091739405 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:534010023360 (534.0 GB) TX bytes:489088324345 (489.0 GB)
Interrupt:16 Memory:fbfe0000-fc000000

eth2 Link encap:Ethernet HWaddr a4:5d:36:11:2e:94
BROADCAST PROMISC MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
Interrupt:17

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:46518 errors:0 dropped:0 overruns:0 frame:0
TX packets:46518 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:19611331 (19.6 MB) TX bytes:19611331 (19.6 MB)

tap0 Link encap:Ethernet HWaddr 76:bc:23:ab:84:9a
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:4829495 errors:0 dropped:0 overruns:0 frame:0
TX packets:70728186 errors:0 dropped:311 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:784617939 (784.6 MB) TX bytes:8231505005 (8.2 GB)

tap1 Link encap:Ethernet HWaddr 26:cc:b7:da:25:f2
UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1
RX packets:24410809 errors:0 dropped:0 overruns:0 frame:0
TX packets:100220174 errors:0 dropped:5449 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:3092858008 (3.0 GB) TX bytes:40917253576 (40.9 GB)

tap2 Link encap:Ethernet HWaddr 22:51:7c:59:70:7d
UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1
RX packets:50267416 errors:0 dropped:0 overruns:0 frame:0
TX packets:147167205 errors:0 dropped:7801 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:5968587001 (5.9 GB) TX bytes:100144429241 (100.1 GB)

tap3 Link encap:Ethernet HWaddr ae:10:77:27:62:c3
UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1
RX packets:65080840 errors:0 dropped:0 overruns:0 frame:0
TX packets:152385679 errors:0 dropped:15728 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:19023991024 (19.0 GB) TX bytes:98250740445 (98.2 GB)

tap4 Link encap:Ethernet HWaddr 5e:19:90:aa:17:0f
UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1
RX packets:15161291 errors:0 dropped:0 overruns:0 frame:0
TX packets:87589776 errors:0 dropped:1780 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:2077782588 (2.0 GB) TX bytes:27030621597 (27.0 GB)

tap5 Link encap:Ethernet HWaddr 12:a3:e6:8d:4f:c6
UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1
RX packets:22160744 errors:0 dropped:0 overruns:0 frame:0
TX packets:97860579 errors:0 dropped:1567 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:2878196549 (2.8 GB) TX bytes:39396549102 (39.3 GB)

tap6 Link encap:Ethernet HWaddr 7e:23:fe:43:a9:38
UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1
RX packets:94446 errors:0 dropped:0 overruns:0 frame:0
TX packets:65936623 errors:0 dropped:25 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:10875606 (10.8 MB) TX bytes:4033455894 (4.0 GB)

tap7 Link encap:Ethernet HWaddr 96:a7:0d:30:be:dc
UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1
RX packets:29068871 errors:0 dropped:0 overruns:0 frame:0
TX packets:112341747 errors:0 dropped:9326 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:4127431405 (4.1 GB) TX bytes:59931967825 (59.9 GB)

br0 - root local interface connected to VLAN
br0:* - aliases local IPs for rinetd
eth* - bonding
tap* - OpenVPN instance

3. Softether build:
softether-vpnserver-v4.08-9449-rtm-2014.06.08

4. SoftEther VPN component:
L2TP over IPsec Server Function Enabled |Yes
Raw L2TP Server Function Enabled |Yes
EtherIP / L2TPv3 over IPsec Server Function Enabled|Yes

5. This server have the firewall and all UDP ports open.

6. VPN Server/vpn>SecureNatStatusGet
SecureNatStatusGet command - Get the Operating Status of the Virtual NAT and DHCP Server Function (SecureNat Function)
Item |Value
-------------------------+----------
Virtual Hub Name |vpn
NAT TCP/IP Sessions |47 Session
NAT UDP/IP Sessions |20 Session
NAT ICMP Sessions |0 Session
NAT DNS Sessions |0 Session
Allocated DHCP Clients |3 Client
Kernel-mode NAT is Active|No

VPN Server/vpn>SecureNatHostGet
SecureNatHostGet command - Get Network Interface Setting of Virtual Host of SecureNAT Function
Item |Value
-----------+-----------------
MAC Address|00-AC-34-21-35-B5
IP Address |192.168.30.1
Subnet Mask|255.255.255.0

About my problem:
This server using as IPsec/l2tp vpn server for users, all users connect to server and working via VPN but users with Linux (Mint, Ubuntu) have problems with disconnects and droped file transfer.
E.g. I'am connect from Linux computer to another linux server via SSH, work few minutes and get connection reset: Broken pipe
Also when I tried tranfer files from my comp to server or from server to me I'm get/put only few bytes and transfer frozen:
hellname@null /tmp $ rsync -av --progress test.img cc1.local:~/.
sending incremental file list
test.img
32768 0% 0.00kB/s 0:00:00 ^C
rsync error: received SIGINT, SIGTERM, or SIGHUP (code 20) at rsync.c(549) [sender=3.0.9]
hellname@null /tmp $ rsync -av --progress test.img cc1.local:~/.
sending incremental file list
test.img
2129920 1% 1.79MB/s 0:01:11 ^C
rsync error: received SIGINT, SIGTERM, or SIGHUP (code 20) at rsync.c(549) [sender=3.0.9]

I'm tried tune sysctl parameters but not effect. Can you help me please? I.f you need more information about my problem, server or other please tell me. Thanks a lot.

[hellname]

Something else, users that run on Windows no have problems.

[hellname]

Somebody help me please with my issue.

[hellname]

I solved my problem. Setup softetervpn without secureNAT and enable Local Bridge. Currently l2tp work fine.