Symptoms: When you try to use your modem on a
Windows computer, you may receive an error message similar to the following:
Error 633 Modem is already in use, or is not configured for Remote Access
dial out or The port is in use.
Resolutions: 1. Verify no other applications
that are using the modem. You can open Task Manager to check that by press
CTRL+ALT+DEL. Another way to test it is reboot the computer.
2. This behavior may occur when another device with a driver, for example
outdated Palm Pilot software, conflicts with the modem.
3. Telephone.ini or unimdm.tsp is missing or damaged.
4.
Make sure the modem is setup correctly and may
apply SP.
5. Removing and reinstalling it, or apply the new drive may fix the
problem.
6. Make sure no two ISDN installed on the same machine and attempt to
connect to the same server.
Error
638: The request has timed out
Refer to
Error 721
Error 645:
Internal authentication error (also re:
error 913), or
Dial-Up Networking could not
complete the connection to the server.
Resolutions:
1) uncheck
require encrypted password under the Server Types tab.
2) Make sure you are entering your correct username and
password when connecting.
3) Uninstall and reinstall the Dial Up
adapter. 4) Refer to error 619 resolution - add the vpn to the
appropriate group.
Error 649. The
account does not have permission to dial-in.
Resolution:
1) This error can occur if the user name is the same as the domain name.
2) This error can occur if the username is 'system'.
3) This error can occur if dialing in to a Windows NT Remote Access Server and
your password has expired.
4) Make sure the user is allowed to dial-in.
5) Check PPTP filtering. For the test, disable PPTP
filtering on the server (Net Stop RASPPTPF), and see if you can establish a
non-filtered connection.
VPN Error 649 - The account does not have
permission to dial-in - Case Study
Error 649 - Login
failed: username, password, or domain was incorrect
Error 650:
The Remote Access server is not responding.
Resolution:
1) Proxy or firewall block like port 1723 and IP GRE 74.
2) Check the server type and uncheck most of them.
3) Make sure you type correct information in logon screen.
4) Check PPTP filtering. For the test, disable
PPTP filtering on the server (Net Stop RASPPTPF), and see if you can establish
a non-filtered connection.
Error 678: There was not answer.
Resolution:
1) you are dialing the wrong number.
2) make sure you have good connection.
3) If using VPN, make sure the port 1723 and IP Protocol 47 (GRE) are opened.
Error 682:
When VPN clients try to remotely
log on to your network, they may be denied access. Users may receive one of
the following error messages: Error 628: The connection was closed, and see
the Verifying Username and Password dialog
box. This issue may occur if your VPN server is located behind a Linksys
BEFSR41 router, Proxy or ISA.
Resolution: To resolve Linksys BEFSR41 router
issue, update the firmware for your Linksys BEFSR41 router. To resolve Proxy
or ISA issue, obtain the latest service pack for ISA Server 2000.
Error 691:
Access denied because username and/or password is invalid on the domain.
Resolution:
1) Verify the logon ID and password
are correct.
2) Make sure the Include Windows logon domain
check box is unchecked in the Options tab of the dial-up
connection's Properties dialog box.
3) Make sure the dial-up connection's security option is correctly configured
to use the Require secured password setting.
4) Delete all of the *.pwl files and reboot if you are using win9x.
5) Try another logon ID or create a new Logon ID because the profile may be
damaged.
Error 711:
When attempting to start the Routing and Remote Access Service, you may
receive "The Routing and Remote Access service terminated with
service-specific error 711" and Event ID: 7024 in the System Event log of the
server shows. This behavior may occur because the Routing and Remote Access
Service is unable to start if the Remote Access Connection Manager service,
Remote Access Auto Connection Manager, and the Telephony service are disabled.
RESOLUTION: to resolve this behavior, you must
use the Services Administrative tool to set the
Startup Type of all the Remote
Access Connection Manager service, Remote Access Auto Connection Manager, and
the Telephony service to Manual..
After you have made these settings, you can restart the Routing and Remote
Access Service.
Error 720: No
PPP control protocols configured.
Resolution:
1) make sure both RAS server and client have the correct protocol setup.
2) make sure the NetBIOS interface has being installed and the NetBIOS
binding has being enabled. The NetBIOS interface is required for establishing
logical names and sessions on the network for Windows NT/9x/ME.
Error 721:
Remote PPP peer or computer is not responding. If you have tried many thing
other people suggest like rebooting, reloading hardware and re-installing the
VPN or dial in connection, you still get the same problem. I will suggest to
check the router settings and make sure TCP Port
1723, IP Protocol 47 (GRE) are opened. Also make sure that the router
has the PPTP enabled and not firewall block the traffic. On the RAS server,
check the DHCP settings.
Case Studies – VPN
error 721 and 800
Error 733: the
PPP control protocol for this network protocol is not available on the
server.
Resolution:
1) Ensure that the TCP/IP protocol is installed on your RAS
server and that the TCP/IP protocol is selected in the Server Settings of the
Network Configuration option of the Remote Access Setup dialog.
2) If you have the "Use DHCP to assign remote TCP/IP client addresses" option
selected for the TCP/IP protocol in the RAS Server Settings, then ensure that
you have installed DHCP and that it is not disabled.
3) Ensure that all of the bindings for TCP/IP are enabled in the Bindings tab
of the Network dialog of the Control Panel. Be sure to inspect the TCP/IP
Protocol and WINS Client (TCP/IP) bindings for all
adapters, all protocols, and all services. If the TCP/IP bindings are corrupt, you may have to
reinstall TCP/IP and or RAS in order to clean up the bindings.
4) To fix
this issue, you may setup a static pool of IP addresses for VPN clients.
Error 734
- The PPP link control protocol terminated.
Resolutions:
1. this is most like security issue, for example, you set to send encrypted
passwords and your RAS server does not support encrypted passwords, or reverse
situation. Check the security settings on both sides.
2. if multi-link negotiation is turned on for the single-link connection,
disable it.
3. This error may occur if you are using user-defined callback in your DUNS
setup.
4. Also refer to error 691.
Error 735
- The requested address was rejected by server.
Make sure you don't setup static IP on the VPN
client and let the VPN server assign IP.
Error 736 - The remote computer terminated the control protocol.
1.
This
error indicated that the VPN server is out of available ports/IP addresses.
2. Or if the remote
access server is unable to obtain an IP address from DHCP for the connection.
3. This is probably due to a glitch on
the ISP's end.
4. If it is NT, try to disable PPP LCP
extensions.
Error 741 - The local computer
does not support the required encryption type.
1. Make sure you enter correct
password.
2. Switch from L2TP to PPTP.
3. Enabling 128-bit Encryption for
Routing and Remote Access
Error 769 The
specific destination is not reachable.
Cause: 1. The network card in your computer is not turned on. 2. The dial-up
connection is not listed in the 'dial-up' section
Error 792 - The L2TP Connection Attempt
failed because security negotiation timed out.
Causes: 1. This behavior can occur
because you have a preshared key that is configured on the client, but the key
is not configured on the Routing and Remote Access Service server.
2. VPN server is not a valid machine certificate or is missing.
3. The IPSec Policy Agent service is stopped and started without stopping and
starting the Routing and Remote Access service on the remote computer.
4.The IPSec Policy Agent service is not running when you start the Routing and
Remote Access service.
5. The ISA Server computer is configured to block IP fragments.
Error 797
- The modem could
not be found.
Resolutions:
1. Rebooting the machine that may solve the problem.
2. Remove and then re-install the modem.
3. Check to see if there is an upgrade driver for your modem.
Error
781 - Encryption Failed
Symptom: When connecting to a VPN server, you
may receive this Error 781: The encryption attempt failed because no valid
certificate was found.
Resolution: If your VPN client is trying to use
L2TP/IPSec for the VPN connection, you may receive above message. What you
need to do is switching to a PPTP VPN connection, which doesn't need a
certificate. To do this, open the properties of the VPN connection, choose
the Networking tab, and change the "Type of VPN" to PPTP VPN (default is
Automatic). Also make sure you have good connection. Sometimes, poor
connection can cause this issue too.
Symptom: When you try to enable
ICS, you may receive the following error message: "Error 783: Internet
Connection Sharing cannot be enabled. The LAN connection selected as the
private network is either not present, or is disconnected from the network.
Please ensure that the LAN adapter is connected before enabling Internet
Connection Sharing."
Resolution: When enabling ICS, your computer is
assigned the 192.168.0.1 IP address, and if this address is already in use on
the network, you will get this error message. To fix this problem, disconnect
the computer using the 192.168.0.1 IP address from the network, or change its
TCP/IP settings to use DHCP.
Error 800: Unable to establish the VPN connection. The VPN
server may be un-reachable, or security parameters may not be configured
properly for this connection.
Resolutions:
1) if you have firewall, open TCP Port 1723, IP Protocol 47 (GRE).
2) make sure you can reach the VPN server by using ping. Sometimes,
poor connection can cause this issue too.
3) You may need to updated firmware on a router or firewall if other OS
(win9x/nt/me/w2k) works except XP.
4) The VPN server may not be able to get IP from DHCP for the VPN client. So,
you may want to re-configure VPN host networking settings. For XP pro VPN
host, go to the Properties of the VPN>Network, check Specify TCP/IP address
and Allow calling computer to specify its own IP address, and uncheck Assign
TCP/IP addresses automatically using DHCP.
5) Make sure other secure software blocks your access, for example, if you use
Norton secure software, you may need to add the remote client's IP so that the
client can access.
6) If your VPN running on a Windows RRAS with NAT enabled, you may want to
check the NAT settings.
Case Studies – VPN
error 721 and 800
Error 806: a
connection between your computer and the VPN server has been established but
the VPN connection cannot be completed. The most common cause for this is
that there is at least one internet device between your computer and the
VPN server is not configured to allow GRE protocol packets Verify that
protocol 47 GRE is allowed on all personal firewall devices or routers. if
the problem persists, contact your administrator.
Resolutions:
1) if you have a router/firewall, make sure you open TCP Port 1723, IP Protocol 47 (GRE).
2) make sure you can reach the VPN server by using ping. Sometimes,
poor connection can cause this issue too.
3) You may need to updated firmware on a router or firewall.
4) The VPN server may not be able to get IP from DHCP for the VPN client. So,
you may want to re-configure VPN host networking settings. For XP pro VPN
host, go to the Properties of the VPN>Network, check Specify TCP/IP address
and Allow calling computer to specify its own IP address, and uncheck Assign
TCP/IP addresses automatically using DHCP.
5) Make sure other secure software blocks your access, for example, if you use
Norton secure software, you may need to add the remote client's IP so that the
client can access.
6) If your VPN running on a Windows RRAS with NAT enabled, you may want to
check the NAT settings.
Cases:
VPN
Error 721, 800 or 806
Case Studies – VPN
error 721 and 800
Error 913: A
Remote Access Client attempted to connect over a port that was reserved for
Routers only (also re: Error 629
and 645). The event viewer may also generate the
following event:
Event ID: 20188
Source: RemoteAccess
Description: The user username, attempting to connect on port,
was disconnected because of the following reason:
A Remote Access Client attempted to connect over a port that was reserved for
Routers only.
Resolutions:
1) Enable
Remote access connections. To do
this, go to Routing and Remote Access administrative tool>Ports>Properties,
click the appropriate port (L2TP, Modem, PPTP, LPT1, and so on), and then
click Configure, and then check the
Remote access connections
(inbound only).
2) Double-click the "Incoming Connections" icon on network
connections folder and make sure "Allow VPN Connections" is enabled.