OpenVPN Support Forum

Hello,

I have CentOS 5.5 with OpenVPN 2.1.4 and Windows Clients with OpenVPN 2.1.4 version too. I have to see clients connected into the network (I will have approximately 50 clients connected into this server), so I add client-to-client flag into the server config which you can see bellow. When I copy data between client and server averything works fine, but when I want copy data between client and another client via FTP the communication is 10 times slower and ftp communication crashes and starts again. Applications using UDP packets which communicates between two clients don't work properly too . When I removed comp-lzo from my configuration, then the communication was better, but the problems still exist. I tried change tun and tap, udp and tcp with no improvement.

Do you have any idea what is wrong?

Best Regards.
Myth Rush

mode server
tls-server
proto udp
user openvpn
group openvpn
dev tap
comp-lzo
ifconfig 10.200.0.1 255.255.0.0
ifconfig-pool 10.200.0.2 10.200.255.254 255.255.0.0
tls-auth /etc/openvpn/ta.key 0
ca /etc/openvpn/ca.crt
cert /etc/openvpn/server.crt
key /etc/openvpn/server.key
dh /etc/openvpn/dh2048.pem
client-to-client
client-config-dir /etc/openvpn/ccd
ccd-exclusive
verb 4
mute 3
keepalive 10 120

hi there,

how about using tun instead of tap?

when you try to communicate from one client to another you are actually sending data to server
then data goes to client,client responds to server and finally server sends data back to first client..

what upstream speeds your clients has?

it is normal your client-to-client connection to be slower than your client-server...

cheers,

michael.

Hello,

I tried tun and tap, TCP and UDP with no improvement. Both clients have 10 MB connnection into the Internet. Server has 100 MB connection. When I copy data between client and server (without VPN) the speed is 500 kbps. When I use VPN and copy data between client and server the speed is 500 kbps too. When I copy data between client 1 and client 2 via VPN the speed is 30-40 kbps and crashes...

Best regards.
Myth

can you post some hardware info regarding your server?

cheers,

michael.

Hello,

it is virtual machine which is hosted on the Dell 2950, with two processors Intel Xeon Quad core 2.0Ghz, 8 GB RAM. The memory is shared between all virtual machines, you have lo memory limit garanted 144MB. Sometimes is memory below 50 MB it wavers sometimes very much, processors are shared across all virtual machines too. All virtual machines and tasks have the same priority.

Do you think that the server machine can be the problem? it is fast and stable enough when I copy data between client-server. Only client-client transfers are bad...

Best Regards.
Myth

hi there,

i had a similar problem with you once but the centos
was on a hp blade system...not vm (which hypervisor you are using?)

after 2 weeks of troubleshooting i changed os to ubuntu (same openvpn config)
and everything worked..
maybe was a nic driver issue,who knows..

if you try ftp from one client to a server BEHIND the openvpn do you have the same issue?

cheers,

michael.

Hello,

I am sorry. I don't know which supervisor is there on the virtual machine. This is very cheap VM hosting and they don't give any information about their setup.

No, when I ftp from client to server everything works perfectly.

Best regards.
Myth

hi again,

besides ftp,other services (rdp,smb) work ok?
i mean that if you try to copy a file not via ftp but using windows network browser
the problem still exists?

btw:if you ping from one client to another what time responses you get?

cheers,

michael.

ps:Probably the hypervisor is Kvm...

Hello,

all services are very slow. Working with Smb is horrible, all answers are like on the gumma - very slow and delayed. Copy small files is absolutely tragic. For smal files is the speed around 4 - 10kbsp. For larger files (1MB and more) is the speed 40kbps. Ping is very often 50ms, but sometimes it grows up to 350ms.

Best regards.
Myth