Very slow speed through TAP tunnel between Linux and Windows

[matroskin]

Hello all,

Sorry for my english - it's not my native language.

I have the problem with TAP tunnel between Linux and Windows XP(&7). The tunnel provide Very low speed then i try transfer data over it. Speed about 50 kbyte/s, but i have connection from my ISP at 1500 kbit/s on Server side and 1000 kbit/s on Client side of tunnel. Connection going right - without any error messages. Configs are here:

Client:

Code: Select all

client
dev tap
remote XXX.XXX.XXX.XXX XXXX
proto udp

mtu-test
tun-mtu 1500
tun-mtu-extra 32
mssfix 1450

resolv-retry infinite
nobind
pull
comp-lzo
persist-key
persist-tun
verb 3

ca "....\\ca.crt"
cert "...\\f_client.crt"
key "...\\f_client.key"
tls-auth "...\\ta.key" 1
ns-cert-type server

auth SHA1
cipher AES-256-CBC

Server:

Code: Select all

daemon openvpn
writepid /var/openvpn/pid
status /var/openvpn/status 10
local 192.168.168.99
port 1194
proto udp

comp-lzo
ca /etc/openvpn/keys/ca.crt
cert /etc/openvpn/keys/server.crt
key /etc/openvpn/keys/server.key
dh /etc/openvpn/keys/dh1024.pem
tls-auth /etc/openvpn/keys/ta.key 0

dev tap0
server-bridge 192.168.168.200 255.255.255.0 192.168.168.201 192.168.168.250
mtu-test
tun-mtu 1500
tun-mtu-extra 32
mssfix 1450

keepalive 10 120

auth SHA1
cipher AES-256-CBC

max-clients 10

log-append /var/log/openvpn.log
verb 4
mute 20

user _openvpn
group _openvpn

chroot /var/empty

I already test these positions:

1. Then i try transfer data between server and client without OpenVPN (FTP or SFTP) speed is OK.

2. Then i try transfer data between server and client through Open VPN TUN tunnel speed is OK too.

3. Then i try change MTU parameters at tunnel - speed is LOW, and i have a error message in process of connection.


In process of search solution for my problem, i find the opinion that said - problem in TAP driver for windows OS. Can it opinion be right? I can't find solution at this forum.

P.S.

Yes, I'am really need TAP tunnel. I can't use TUN because I need connections to all host of LAN behind OpenVPN server, but i can't change routing table at Gateway router (it is not OpenVPN server's host).

P.P.S.

Thanks to all, whosever answer. If this problem are solved - please, put the link to the topic.

[janjust]

3. Then i try change MTU parameters at tunnel - speed is LOW, and i have a error message in process of connection.

if you change the MTU setting of the tunnel you also need to change it on the client ; on a Windows 2000/XP system this means a registry change+reboot. You're better off playing with the 'fragment' option first.

Try replacing

mtu-test
tun-mtu 1500
tun-mtu-extra 32
mssfix 1450

by

Code: Select all

fragment 1200
mssfix

P.S.

Yes, I'am really need TAP tunnel. I can't use TUN because I need connections to all host of LAN behind OpenVPN server, but i can't change routing table at Gateway router (it is not OpenVPN server's host).

you could use a non-bridged setup and masquerading on the linux server - there's no need to use bridging for this. It should not be the root cause of the performance issue, however.