Hi , Can anyone pls tell me why I am continuously getting following message in openvpn server log. I have setup openvpn server in Linux box and every thing is Ok till now.Clients are using Windows7. But invalid packets flooding server network.If it can be stopped. Pls help. [code] May 27 08:20:12 server openvpn[16063]: username/xxx.203.202.65:56070 MULTI: bad source address from client [xxx.203.202.65], packet dropped .................... [/code] Config file can be found here - https://forums.openvpn.net/topic10520.html Thanks for your time pada

My Openvpn Server flooded with packets with bad source addr

pada123

Hi ,
Can anyone pls tell me why I am continuously getting following message in openvpn server log.
I have setup openvpn server in Linux box and every thing is Ok till now.Clients are using Windows7.

But invalid packets flooding server network.If it can be stopped.
Pls help.

May 27 08:20:12 server openvpn[16063]: username/xxx.203.202.65:56070 MULTI: bad source address from client [xxx.203.202.65], packet dropped
....................

Config file can be found here - https://forums.openvpn.net/topic10520.html

Thanks for your time
pada

krzee

you are getting this message because a client is sending packets over the tunnel with xxx.203.202.65 as the target. the problem is that there is no way for the server process to know who owns xxx.203.202.65, so it must drop the packet. there are 2 ways to make the error stop:
1) stop sending traffic over the tunnel with source address of xxx.203.202.65
2) add an iroute for the client who is sending that traffic, so then the openvpn server process will know who that ip (or subnet) belongs to.

did you get your old problem fixed too?
Your client log looked like it wasnt adding any routes right, in addition to what maikcat said. if that is still true, be sure that you are always starting the openvpn process as administrator, if it stays the same let us know

pada123

Thanks krzee.

Yes for the earlier problem I got what maik said. But now I am using Linux Server and Windows 7 as Client.
Everything is going fine except bad packet.

I have read you answer ..

For information My client is not in any LAN or behind any firewall ..Its directly connected to Internet and have a Public IP.
xxx.203.202.65 - is the client public IP.
Its the actual IP which VPN server getting when client connects .

As you mentioned ..I am trying to understand those

1) stop sending traffic over the tunnel with source address of xxx.203.202.65

In the given configuration - https://forums.openvpn.net/topic10520.html

Can you please tell me What more do i need to add in client config file ..Because the Client IP xxx.203.202.65 is not static.

What I understand without Openvpn for all outgoing packets source IP is - .xxx.203.202.65

As soon as VPN is connected all packet having source ip -xxx.203.202.65 go through tunnel
and it is replace by virtual VPN Client IP..except packets with destination IP matches with VPN server Ips.

So How can I stop sending packets with source IP - .xxx.203.202.65..

May 27 08:20:12 server openvpn[16063]: username/xxx.203.202.65:56070 MULTI: bad source address from client [xxx.203.202.65], packet dropped

If wee see the Message its telling

  bad[b] source address[/b] FROM client [xxx.203.202.65]

.

We need not block that Source address only..But How do i check that Source IP..
may be I am mixing up..

Pls give me light.
Thanks
pada

krzee

the bad news is that I have seen this before, and have no idea what causes it. Your machine is sending traffic out of tun0 with the source ip of eth0. I have no idea why. It should not be doing this.

pada123

Thanks krzee for your time..Can any other expert Please give some light .Thank you

Mimiko

This is a windows bug. See this: https://forums.openvpn.net/topic8289.html

pada123

Thank you very much Mimiko.