Linux VPN Server

Here are some troubleshooting guides for particular topics.

(1) Your Virtual Network Connection

(2) VPN Troubleshooting Error Messages

(3) VPN Modems Troubleshooting Guide

(4) VPN ISP Troubleshooting Guide.

(1) Your Virtual Private Network Connection

Having trouble connecting to the Internet at home try these steps before calling for help.

1. Do you have an IP address? Try ipconfig /all. If you do not have an IP address reboot your PC. If that doesn’t work power cycle your Cable/DSL modem and routers and reboot your PC again after the network devices are up and stable. Be sure all of your network cables are plugged in tight.

2. After your PC reboots check that your network adapter is active and packets are flowing. Perform the ipconfig /all check again.

3. Check your connectivity by pinging several Internet sites. If that does not work, ping the loopback address 127.0.0.1. If that fails, your adapter may not be working or it is not properly configured.

To check your IP address. From command prompt enter ipconfig /all (as shown in the picture) you https://onlinevpnapp.com/ should see an IP Address and several DNS Server addresses. The domain name system (DNS) is the way that Internet domain names are located and translated into IP addresses and is required for browsing the Internet.

Ping 127.0.0.1 – loopback Test (as shown in the picture). The loopback test is used to check if the IP stack is responding. If it times out or you get an error the problem may occur if any one or more of the following conditions is true:

*The TCP drivers are corrupted

*The network adapter is not working

*Another service is interfering with IP

Check your network adapter, click the Start menu, Settings, Control Panel, and select Network Connections. Double click on the Local Area Connection or the Wireless Adapter whichever one you are using. Be sure its Connected. If you have multiple network cards disable the one you are not using.

There should be Packets displayed in both the Sent and Received counters. If the Received counter is 0 check that the adapter has an IP address. Select Properties.

Click the check boxes for Show icon and Notify me below. A twin PC icon will appear on the lower right portion of the taskbar in the tray area and will flash while sending and receiving packets. You can place your mouse over the icon to get the status and click on it to get more details.

Tracert displays the connection path to the target location and the number of hops. Each hop is the trip from one router to another. Tracert is a handy tool both for understanding where problems are in the network and for determining latency between hops.

Ping is used to determine whether a host exists and is active on the network and can determine the round trip time to the device. You can enter a host name or an IP address if you know it. If the request times out then the host is not reachable because it’s offline or there is a problem with the connection. Try several sites, if none work then ping the loopback address 127.0.0.1 Also, if your DNS is not working or properly configured you can only ping the host with an IP address and you will not be able to browse the Internet.

If you are having intermittent problems, perform a ping -t for 5 to 6 minutes then hit CTRL C to see the results of the test to determine if you are dropping network packets (lost packets). If you are, this usually indicates an ISP problem or Cable/DSL modem problem. See VPN ISP Troubleshooting Guide

(2) VPN Troubleshooting Error Messages

Q1 Error Message: Remote Host not responding: or Unable to Resolve the IP address of the Remote Server

Cause: This indicates that the Contivity VPN Switch never responded to the connection attempt. The problem could either be with the Contivity switch itself, (switch may be down) or your machine may be having a problem resolving the IP address.

Action: Try pinging your destination name (Example: VPN.something.com). If you received a message that says “Request Timed Out” from the ping command, call your ISP to make sure that their DNS is functioning correctly.

Q2 Error Message: Maximum number of sessions reached

Cause: This indicates that the maximum number of users for the account you are using are currently logged on.

Action: If you are the only user with VPN to your account, it is possible to get this error if you restarted a connection immediately after losing the dial-up connection to your ISP. This is because the Contivity VPN Switch takes up to one hour to determine that your connection has been dropped and log you off from your account.

Q3 Error Message: Login failed, Please consult the switch log for further information

Cause: The User Name or the Password is incorrect for the user name entered.

Action: Verify that the User Name you entered is correct and retype the Password before trying the connection again.

Q4 Error Message: The physical connection has been lost

Cause: Your connection to your ISP was disconnected.

Action: Re-establish your connection to your ISP before you re-establish the Contivity connection to the remote network.

Q5 Error Message: The secure Contivity connection has been lost

This message can result due to a number of different reasons, and there are several recommended actions you can take to try and re-connect.

Cause(s):

If you receive this error before the client connects then something is blocking a necessary port (such as ESP port 50). This can result if your firewall is not configured properly and is restricting the necessary port(s).

If you receive this error during a connection and you suddenly get the error it may mean one of the following:

1. Something closed the connection;

2. The VPN Contivity switch where you were trying to connect to thought your client was down or timed out;

3. Your local ISP did something that interrupted your network connection long enough for the VPN Contivity switch to identify your client was not responding;

4. The VPN Contivity switch that you are connected to has either logged your connection off

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