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badri_nana

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Setting Up VPN

Hi,
I am trying setting up VPN connectivity.I am using the vpnclient_linux.tar.I proceeded as per it's instructions.I have a gateway through which I connect to the VPN host.The installation proceeded successfully.When I try to connect,I  get an error.Can you please help me.Thanks a lot for your help & precious time.

The error is as shown below:
# ./vpnclient connect test
Cisco Systems VPN Client Version 4.0.3 (B)
Copyright (C) 1998-2003 Cisco Systems, Inc. All Rights Reserved.
Client Type(s): Linux
Running on: Linux 2.4.20-8 #1 Thu Mar 13 17:54:28 EST 2003 i686
 
Initializing the VPN connection.
bind: Address already in use
bind: dst addr 0.0.0.0 port 500
bind: Address already in use

I changed the ipchains file to contain the proper IP.Still it gives this  error.Can anyone help me how to solve this?

Thanks a lot.

Regards
Badrinarayanan
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Mercantilum
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This error (bind: Address already in use) means that locally the port is already in use, I guess it is  the port 500.
Either the port is already taken by another application or it is a residue of a previous use.

Try
   netstat -a | grep 500
to see what takes the port.

Actually the ports < 1024 are usually kept for system / known services.

Can you change the config the port (500?) to something else, let  say 8000.
Ensure your firewall cope with the change.

Regards
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badri_nana

ASKER

Hi,

Thanks for the info.What you said what was right.I had installed two VPN client softwares.One of them was utilising the port. I killed the  two processes.After doing all configurations, I have set NAT also. Now I don't get this error bind: 0.0.0.0 in port 500 already in use.
I get a new error "
Initializing the VPN connection.
Secure VPN Connection terminated locally by the Client
Reason: Failed to establish a VPN connection.
There are no new notification messages at this time.

Can anyone suggest where I can see log file or the cause of this error? Is there any command for this?
I have a CISCO VPN client installed here.I am able to connect through a Windows PC to the VPN.Through Linux it is giving me this problem.I am using IPSec & UDP port 500 to connect to a gateway.

Regards
Badrinarayanan
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Mercantilum
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> .. I have set NAT also ..
where have you done this, and how? Please post exact commands.
Also, if you're using NAT, is there another router (DSL, or whatever) on your site?
Is the remote Cisco configured to allow NATted VPN connections?
With regard to Mercantilum's comments about port 500 being in use this is correct.
VPN normally uses the IPSEC protocol and this uses UDP port 500 for IKE (exchanging the encryption keys) and therefore you cannot choose to use a different port.
As Mercantilum said you need to use the netstat command to find out what other process is listening on port 500 and stop it.