A virtual private network (VPN) is a way to use a public telecommunication infrastructure,
such as the Internet, to provide remote offices or individual users with secure access to
their organization's network. In the past, companies would have rented expensive systems of leased lines to build
their VPN only they could use. A VPN provides the same capabilities at a much lower cost.
A VPN works by using the Internet while maintaining privacy through security procedures and
tunneling protocols such as the Layer Two Tunneling Protocol (L2TP) or IPSec. In effect, private data,
being encrypted at the sending end and decrypted at the receiving end, is sent through a "tunnel" that
cannot be "entered" by any other data.
Why IPSec is strong ?
Definition: IPSec (Internet Protocol Security) provides security services at the IP layer
by enabling a system to select required security protocols, determine the algorithm(s)
to use for the service(s), and put in place any cryptographic keys required to provide
the requested services. The IPsec architecture is described in the RFC-2401 (www.ietf.org RFC-2401).
IPSec has been selected to be embedded in IPv6. IPSec is strong because it was designed to be
strong and replace some older methods like PPTP.
Today IPSec is the most secure way to access the corporate network from the Internet, here are some elements why:
Strong encryption mechanisms like Encapsulated Security Payload (ESP) using DES, 3DES, AES with long key length (i.e. 128, 192, 256)
Strong authentication of parties identity with the use of X-Auth and Certificate with long key length (i.e 1536, 2048)
Use of Internet Key Exchange (IKE) and ISAKMP to automatically exchange keys and mutual authentication.
Protection against denial of service attacks. The IPSec protocols use a sliding window. Packets are numbered and only accepted if they fit the window.
Use of USB Stick, USB Token in conjunction with IPSec Client software to protect identity/authentication information and VPN configurations (i.e. a TheGreenBow specific feature).
What is NAT Traversal and do you support it ?
Definition: Network Address Translation (NAT) is designed to decrease IT manager frustration for
scarce public IP addresses. A NAT device takes a packet’s originating private IP address,
translates that address into a public IP address, before sending the packet across the Internet
to its destination. NAT devices use an internal table to keep track of translated addresses but
unfortunately manipulate the packet’s original IP header, impacting IPSec ability to function.
IETF (Internet Engineering Task Force) group worked out a solution called NAT Traversal
(NAT-T RFC-3193). NAT Traversal is now widely implemented in routers and appliances.
The differences between Transport mode and Tunnel mode can be defined (www.ietf.org RFC-2401) thought
the following network configurations:
Tunnel Mode is most commonly used whenever either end of a security association is a
security gateway or both ends of a security association are security gateways, the security gateway
acting as a proxy for the hosts behind it. Tunnel mode encrypts both payload and the whole header (UDP/TCP and IP).
Transport Mode is used where traffic is destined for a security gateway and the security
gateway is acting as a host e.g. SNMP commands. Transport Mode encrypts only the data portion and
leaves the IP header untouched.
Computer authentication by IPSec is performed by using preshared keys or computer certificates.
A pre-shared key identifies one party during Authentication Phase. Per definition, "Pre-shared"
means you have to share it with another party before you can establish a secure VPN tunnel.
The strongest method of authentication is the use of a PKI and certificates. However, smaller organizations
cannot afford the implementation of a PKI system and a well managed preshared key method can be easier and
just as powerful.
Please see our IPSec versus WiFi page where we look at WEP, 802.11i and we compare technologies.
What is DPD ?
DPD or "Dead Peer Detection" is an Internet Key Exchange (IKE) extension (i.e. RFC3706)
for detecting a dead IKE peer. This mechanism is used by the Redundant Gateway feature.
TheGreenBow IPSec VPN Client software
Which Windows versions are supported ?
Windows 98/98SE.
Windows Millennium.
Windows 2000. Win2000 all service packs.
Windows NT4.
Windows XP. WinXP all service packs, including SP2.
Windows Server 2003.
Windows Vista 32-bit
Which languages are supported ?
TheGreenBow IPSec VPN Client is now available in many languages (e.g. English, French, German, Portuguese, Spanish, ...). Check our supported languages list, increasing daily, to find your language.
The language can be selected during software installation of the IPSec VPN Client.
How to localize the IPSec VPN Client?
Do you want to have TheGreenBow IPSec VPN Client in your own language? Go to IPSec VPN Client localization, download and translate in your own language the IPSec VPN Client strings file.
The localization process is very simple and the translation in your language will be available on our next release.
Which are the compatible Gateways ?
TheGreenBow IPSec VPN Client is compatible with all IPSec routers compliant to the existing standards (IKE & IPsec). Check our Certified VPN Products list, increasing daily, to find your VPN gateway.
If the equipment you are looking for is not contained in this list, please contact our tech support and we will work with you to certify it. We will need configuration file, log file from "Console" window and a screenshot of the router configuration page.
How to connect the IPSec VPN Client to Linksys VPN router ?
We've made available for download VPN Configuration Guides for most of the gateways we support on our web site support section, and there are some on Linksys. VPN Configuration Guides are either written by our partners or by our engineering team.
We do support Linksys RV082 and Linksys BEFVP41. You might want to look at our answer about Linksys WRV54G.
How to setup TheGreenBow IPSec VPN Client using Cisco ?
We've made available for download VPN Configuration Guides for most of the gateways we support on our web site support section, and there are some on Cisco. VPN Configuration Guides are either written by our partners or by our engineering team.
We do support Cisco gateways like Cisco PIX501.
Do you support NAT Traversal ?
Yes. We do support NAT Traversal Draft 1 (enhanced), Draft 2 and 3 (full implementation). IP address emulation.
Including NAT_OA support
Including NAT keepalive
Including NAT-T aggressive mode
Does TheGreenBow IPSec VPN Client support DNS/WINS discovering ?
Yes, the IPSec VPN Client does support le "Mode-Config". "Mode-Config" is an Internet Key Exchange
(IKE) extension that enables the IPSec VPN gateway to provide LAN configuration such as DNS/WINS
server addresses to the remote user's machine (i.e. IPSec VPN Client). In case "Mode-Config" is
not supported by remote gateway, DNS and WINS server IP addresses of the remote LAN can be defined
into the IPsec VPN Client, to help users to resolve intranet addressing.
Is TheGreenBow IPSec VPN Client compatible with Linksys WRV54G ?
TheGreenBow IPSec VPN Client is fully certified with Linksys WRV54G firmware 2.37 and later. Please download Linksys WRV54G VPN Configuration Guide.
The Linksys WRV54G firmware 2.25.2 does not accept IPSec connexions from any IPSec VPN Clients with dynamic IP addresses. However, there is a workaround. You need to set up IPSec VPN Client's IP address in the Linksys configuration.
Linksys has released a newer firmware since then. You might want to test it: click here
Which port is needed by TheGreenBow IPSec VPN Client ?
UDP port 500 and UDP port 4500 must be open and ESP protocol (protocol number 50) must be allowed.
Is it possible to use TheGreenBow IPSec VPN Client through Microsoft ISA Server 2000 and 2004 ?
According from Microsoft support, in most cases, IPSec VPN traffic does not pass through ISA Server 2000.
For more details about ISA server 2004, read Q838379 in Microsoft Knowledge Base
What must be filled in Phase 2 field "VPN client address" ?
This field is the virtual IP address that the IPSec VPN client will have inside the remote subnet. With most of VPN gateways, this address must not belong to the remote network subnet.
For example, if you use a VPN gateway with a subnet 192.168.0.0/255.255.255.0, you should use in "VPN Client address" a value like 192.168.100.1 or 10.10.10.1.
Take the case you choose an IP address non-used in the subnet like 192.168.0.200. When the IPSec VPN Client is sending a TCP or an UDP packet to a target remote computer 192.168.0.x, this target will send inside its subnet an ARP request in order to get IPSec VPN Client MAC address and reply directly to it. But, this request cannot receive any answer because the client is not physically present inside the subnet. So, initial packets from the client will not be answered.
If your VPN gateway can answer this ARP request for the IPSec VPN Client, you can fill "VPN Client address" field with an IP address belonging to remote subnet.
You might want to download our IPSec VPN Client User Guide.
Windows(NT) is unable to find/start the TGBSTARTER service
Windows NT may not be able to start the service "TgbIKE Starter". The error message tells the user Windows is unable to find TgbStarter, despite the fact it is actually in the system directory.
This is due to a wrong registry configuration. To solve the problem, check the following key:
Is it possible to hide the graphical user interface i.e. "silent" mode ?
It is possible to run the standard IPSec VPN Client setup in "silent" mode. You need to download
the whole procedure described is this document: VPN Deployment Guide
Is TheGreenBow IPSec VPN Client compatible with Linksys RV082 or BEFVP41 ?
Yes. It is possible to define a Redundant Gateway in the IPSec VPN Client. Redundant Gateway can offer
to remote users a highly reliable secure connection to the corporate network. The Redundant Gateway
feature allows TheGreenBow IPSec VPN Client to open an IPSec tunnel with an alternate gateway in case
the primary gateway is down or not responding. Remote gateway failure is detected by "Dead Peer
Detection" function.
Can IKE Port be modified ?
Yes. A specific IKE Port can be set. To do so, go to global 'Parameters' in the Configuration Panel and enter the right port into the 'IKE Port' field.
What are TgbStarter.exe and TgbIke.exe ?
TgbStarter.exe and TgbIke.exe are components of TheGreenBow IPSec VPN Client.
TgbStarter.exe is the software daemon component (ran as a service)
TgbIke.exe is the IPSec/IKE run-time of the software.
The Software Activation doesn't succeed.
When I try to activate the software, it doesn't succeed (I got an error message)
You can also get your software activated at anytime, by following the procedure described on our Manual Software activation.
What is the VPN Configuration for test?
A test VPN Configuration is VPN configuration designed by TheGreenBow Techsupport team to connect
to our online IPSec VPN gateways and servers. Those are always live and you can use it to test your
network environement at any time. The test VPN Configuration is embedded into the IPSec VPN Client.
Check out online help or download the default VPN Configuration file below.
Can I get temporary license numbers that I can use during my tests?
Yes, license can last several weeks. For further details, contact our sales department.
How to launch my CRM app automatically when IPSec tunnel to my corporate intranet opens ?
It is possible. Go to Configuration Panel>Phase2 and click on scripts. In the Script window,
you can select the application you want to start before or after a tunnel opens or closes.
Does IPSec VPN Client Software support two-way authentication keys and Tokens?
Yes. TheGreenBow supports several two-factor and two-way authentication Tokens to store users, personal credentials, such as private keys, passwords and digital certificates. Please see the Certified Token List.
How to connect to a remote Windows Domain by using the 'Start before Windows logon' feature?
To make it work, please proceed through the following steps:
Go to menu 'File' > 'Preferences', select 'Start VPN Client before Windows logon'.
Go to 'P2 advanced', select 'automatically open this vpn tunnel when client starts'.
Go to 'P2 advanced', select 'automatically open this tunnel on traffic detection'.
Now, please be aware that, due to the specificity of this functionality, it can only work with an IPSec VPN Client software that
has been already activated. As long as the IPSec VPN Client software remains in trial mode, it will start only after the user
clicked on 'Evaluate', and thus, after Windows logon of course. As a consequence, this is the only feature which cannot be tested
with a demo version.
Note: Because users can not check if the tunnel is opened, as Windows logon is not done yet, the best way to test your
VPN Configuration is to define a 'Remote VPN Client address' (i.e. panel 'Advanced Phase2') and try to ping this IP address
from the remote network. If ping is responding then tunnel is opened and your VPN Configuration is correct. For this test to work,
a route might have to be added on the VPN Router/Firewall to reach the VPN Client.
Troubleshootings
"I have message XXXXX in the console". What does it mean ?
We do make available for download a complete guide of messages from TheGreenBow IPSec VPN Client console with explanations and resolving hints. If this document does not help you, send us all the exchanges with RECV and SEND lines. Keep log levels to "0" and click on "Save file". Log file can be found in Program Files \Sistech \TheGreenBow \LogFiles.
No response from the VPN server
If you have the following logs, that means the remote VPN server does not answer to client’s IKE requests.
115317 Default (SA Cnx-P1) SEND phase 1 Main Mode [SA][VID]
115319 Default (SA Cnx-P1) SEND phase 1 Main Mode [SA][VID]
115321 Default (SA Cnx-P1) SEND phase 1 Main Mode [SA][VID]
115323 Default (SA Cnx-P1) SEND phase 1 Main Mode [SA][VID]
Take a look at remote VPN server logs and check if requests from the client are received. If you find no trace, IKE requests must have been dropped somewhere. Check any firewall (including computer Personal Firewall) that can be found between the IPSec VPN client and the VPN server.
VPN is up but I can't ping ?
When logs look like the ones below, the IPSec VPN tunnel is established. Now you should be able to ping any devices onto your VPN server LAN. TheGreenBow IPSec VPN Client configuration is correct.
If you still cannot ping the remote LAN, here are a few guidelines:
Check Phase 2 settings : VPN client address and Remote LAN address. Usually, client IP address should not belong to the remote LAN subnet (read also What must be filled in Phase 2 field "VPN client address" ?)
Once tunnel is up, packets are sent with ESP protocol. This protocol can be blocked by firewall. Check that every device between the client and the VPN server does accept ESP
Check your VPN server logs. Packets can be dropped by one of its firewall rules.
Check your ISP support ESP
If you still cannot ping, follow ICMP traffic on VPN server LAN interface and on LAN computer interface (with Ethereal for example). You will have an indication that encryption works.
Check the “default gateway” value in VPN Server LAN. A target on your remote LAN can receive pings but does not answer because there is not “Default gateway” settings.
You cannot access to the computers in the LAN by their name. You must have specified their IP address inside the LAN.
For full trace with explanations and resolving hints, please see our Troubleshooting document.
"PAYLOAD MALFORMED" error (Wrong Phase 1 [SA])
If you have a "PAYLOAD MALFORMED" error, like this sequence of events, check if the IKE algorithms are the same on each side of the VPN tunnel.
114920 Default (SA Cnx-P1) SEND phase 1 Main Mode [SA][VID]
114920 Default (SA Cnx-P1) RECV phase 1 Main Mode [NOTIFY]
114920 Default exchange_run: exchange_validate failed
114920 Default dropped message from 195.100.205.114 port 500 due to notification type PAYLOAD_MALFORMED
114920 Default SEND Informational [NOTIFY] with PAYLOAD_MALFORMED error
For full trace with explanations and resolving hints, please see our Troubleshooting document.
"INVALID COOKIE" error
If you have an "INVALID COOKIE" error, it means that one of the endpoint is using a SA that is no more in use. Reset the VPN connection on each side.
115933 Default message_recv: invalid cookie(s) 5918ca0c2634288f 7364e3e486e49105
115933 Default dropped message from 195.100.205.114 port 500 due to notification type INVALID_COOKIE
115933 Default SEND Informational [NOTIFY] with INVALID_COOKIE error
For full trace with explanations and resolving hints, please see our Troubleshooting document.
"NO KEYSTATE" error
If you have a "no keystate" error, check if the preshared key is correct or if the local ID is correct (see " Advanced " button). You should have more information in the remote endpoint logs.
115317 Default (SA Cnx-P1) SEND phase 1 Main Mode [KEY][NONCE]
115319 Default (SA Cnx-P1) RECV phase 1 Main Mode [KEY][NONCE]
115319 Default (SA Cnx-P1) SEND phase 1 Main Mode [ID][HASH][NOTIFY]
115319 Default ipsec_get_keystate: no keystate in ISAKMP SA 00B57C50
For full trace with explanations and resolving hints, please see our Troubleshooting document.
"received remote ID other than expected" error
If you have a "received remote ID other than expected …" error, the " Remote ID " value (see " Advanced " Button) does not match what the remote VPN endpoint is expected.
120351 Default (SA Cnx-P1) SEND phase 1 Main Mode [ID][HASH][NOTIFY]
120351 Default (SA Cnx-P1) RECV phase 1 Main Mode [ID][HASH][NOTIFY]
120351 Default ike_phase_1_recv_ID: received remote ID other than expected
For full trace with explanations and resolving hints, please see our Troubleshooting document.
"NO PROPOSAL CHOSEN" error
If you have a "NO PROPOSAL CHOSEN" error (hereafter), check that the "Phase 2" algorithms are the same on each side of the IPSec VPN Tunnel.
For full trace with explanations and resolving hints, please see our Troubleshooting document.
"INVALID ID INFORMATION" error
If you have a "INVALID ID INFORMATION" error, check if "Phase 2" ID (local address and network address)
are correct and match what is expected by the remote VPN endpoint. Check also ID type. If network mask is not
checked, you are using an IPV4_ADDR type (and not a IPV4_SUBNET type).
For full trace with explanations and resolving hints, please see our Troubleshooting document.
DELL or HP laptops with Broadcom Chipset
TheGreenBow recommends customers using a Broadcom chipset integrated with some Dell or HP laptops to
update driver bcmwl5.sys to the most recent release. This driver causes blue screen intermittently even
if our IPSec VPN client is not installed.
Intel Adapter Switching Utility
Intel Adapter Switching Utility causes blue screen when TheGreenBow IPSec VPN Client is installed.
If you have an Intel Pro/Wireless 2100 or 2200, follow these steps in the given order.
- Go to the Start/Control Panel/Add\Remove Programs. Remove the Intel PROset item
- Go to the Start/Control Panel/System.
Select the hardware tab and press the device manager button.
In the device manager, click on the plus sign to expand the Network Adapters item.
Select Intel PRO/Wireless LAN 2200 (or 2100) adapter and right click.
Select Uninstall from the pop-up menu.
- Restart the computer.
Upon reboot the laptop will re-detect the wireless card and install the drivers for it. It will not
intall the Intel PROset drivers. The wireless card should still function, but the added functionality
of the adapter switching will not be available. Windows will then manage the wireless profiles instead
of the Intel PROset utilities.
"Default UDP create:[...] must exist as a listener too"
Problem: the following message appears in the console :
205618 Default udp_create: xxx.xxx.xxx.xxx: 500 must exist as a listener too
205618 Default exchange_establish: transport "udp" for peer "CnxVpn1-P1" could not be created
Solution: This error occurs when the client cannot create a socket for communicating outside. It can be due to the fact that this IP
address is invalid or not used any more. Check if this address still exists. Usually, this error occurs when a specific IP address was
selected in the "Interface" dropdown list and saved instead of "*".
I cannot uninstall IPSec VPN Client software
Problem: I cannot uninstall IPSec VPN Client software, it always asks to first uninstall the previous version.
Solution: You can use our tool
to clean the remaining components of IPSec VPN Client software.
How reporting bug when IKE Daemon crashes ?
You can follow the process given in this page: Reporting Bugs.
Issues with TheGreenBow drivers on Windows Vista
We strongly recommend users on Windows Vista to upgrade their network adapter drivers with Windows Update. This action can prevent
from driver crashes in some network configurations. Also, Windows Vista bug fix pack KB938194 should be installed. More details and
download are available on http://support.microsoft.com/?kbid=938194.
Unable to open a VPN tunnel under Vista, problem with Vista Firewall?
Once TheGreenBow VPN Client installed on Vista, it might be impossible to open a VPN tunnel. The opening of the VPN tunnel remains
blocked with the following IPSec messages (use the IPSec VPN Client console):
115317 Default (SA Cnx-P1) SEND phase 1 Main Mode [SA][VID]
115319 Default (SA Cnx-P1) SEND phase 1 Main Mode [SA][VID]
This can happen on Windows Vista because the Vista Firewall can forbid IPSec communications.
TheGreenBow VPN IPSec 4.2: The software automatically creates new rules into the Windows Vista Firewall during software installation so that IPSec VPN traffic is enabled (see "windows firewall" in the User Guide).
TheGreenBow VPN IPSec 4.1 (and previous): To allow IPSec communications (or verify that they are authorized or restricted), please proceed as follows:
Open "Windows Firewall with Advanced Security".
screenshot
Select in the left menu "Inbound Rules", then in the right column "New Rule...".
screenshot
Select "Port" and then click on "Next".
screenshot
Select "UDP" and the "Specific local ports," then enter two values 500 and 4500 separated by comma (i.e. "500,4500"). Click on "Next".
screenshot
Verify that "Allow the connection" bullet is selected. Click on "Next".
screenshot
Make sure this rule applies to all Profiles. Click on "Next".
screenshot
Assign a name to this new rule. Click on "Finish".
screenshot
The new rule is created.
Select in the left column "Outbound Rules" and in the right column "New Rule...", and configure exactly the same rule (i.e. UDP ports 500 and 4500, VPN Outbound).
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Windows Vista 32-bit
