Hi folks,
I know Linux well, but started to play with openvpn just yesterday.
I am making tunnel between WinXP notebook and Linux desktop
over 10Mbit link. One switch is between them, no routers.
Linux: 2.6.6
WinXP: ver reports "5.1.2600"
Linux side is compiled from source, Win side installed from
binary openvpn-2.0_beta1-install.exe
I run openvpn --config cfg on both sides.
Linux side config:
remote 1.1.1.3
port 8000
proto udp
dev tun
ifconfig 2.1.1.2 2.1.1.1
secret key
ping 10
verb 5
mute 10
Key file is the same on both sides.
WinXP side config is identical except:
remote 1.1.1.2
ifconfig 2.1.1.1 2.1.1.2
Tunnel is established without problems. Then I stress test it
with three instances of large packet flood ping:
# ping -A -s1444 2.1.1.1
typically it looks like this:
CPU load eth in out tun in out
================ ============== ==============
20:21:42 cpu [SSSUUU....] eth0 379k 362k tun0 329k 333k
20:21:43 cpu [SSSUUU....] eth0 357k 343k tun0 314k 316k
20:21:44 cpu [SSSUU.....] eth0 276k 290k tun0 240k 267k
20:21:45 cpu [U.........] eth0 97k 67k tun0 84k 61k
20:21:46 cpu [SSD.......] eth0 60k 38k tun0 34k 34k
20:21:47 cpu [SU........] eth0 158k 138k tun0 125k 126k
20:21:48 cpu [SSSUUU....] eth0 299k 300k tun0 267k 277k
20:21:49 cpu [SU........] eth0 126k 117k tun0 93k 107k
20:21:50 cpu [U.........] eth0 24k 14k tun0 12k 12k
20:21:51 cpu [SSU.......] eth0 29k 18k tun0 15k 15k
...
and sometimes even:
20:28:11 cpu [SSSUU.....] eth0 284k 289k tun0 263k 267k
20:28:12 cpu [SSUU......] eth0 248k 307k tun0 230k 284k
20:28:13 cpu [S.........] eth0 0 239k tun0 0 221k
20:28:14 cpu [U.........] eth0 0 242k tun0 0 224k
20:28:15 cpu [..........] eth0 0 240k tun0 0 222k
20:28:16 cpu [SSU.......] eth0 0 239k tun0 0 221k
20:28:17 cpu [..........] eth0 0 242k tun0 0 224k
20:28:18 cpu [..........] eth0 0 244k tun0 0 225k
20:28:19 cpu [..........] eth0 0 242k tun0 0 224k
20:28:20 cpu [..........] eth0 0 240k tun0 0 222k
20:28:21 cpu [SSU.......] eth0 12k 236k tun0 11k 218k
20:28:22 cpu [SU........] eth0 113k 321k tun0 104k 299k
...
i.e. XP side did not respond to pings!
I looked at 'networking' tab in TaskMan. I see that
incoming traffic for XP is larger that outgoing one,
this verifies that XP did receive those packets over
'normal' interface. However, tunnel interface have
incoming==outgoing, always. Does XP tun drops
incoming packets??
CPU load on XP is ~75%, i.e. it does not hit 100%
I tried pinging non-tunneled link with same ping.
It gives steady 0.5 Mbyte/s each way. No dropouts.
To sum up:
* opnvpn bandwitdh vary too much.
* it doesn't reach ~0.5Mbyte/s.
* sometimes XP side drops packets.
Are these problems known? Do you need more info?
How can I help?
--
vda
