TheGreenBow IPSec VPN Client Configuration Guide
ZyXEL ZyWALL 35 firmware 4.01
WebSite: Contact: http://www.thegreenbow.com support@thegreenbow.com
IPSec VPN Router Configuration
Property of TheGreenBow Sistech SA - Sistech 2001-2006

Table of contents

1 1.1 1.Introduction..... 3 Goal of this document.... 3 VPN Network topology.... 3 Set up ZyWALL 35..... 4 2.1 Prepare ZyWALL's built in Certification Authority... 4 2.2 Create RoadWarrior VPN certificate 2.3 Configure a VPN tunnel 6
Set up TheGreenBow IPSec VPN Client 3.1x... 10 3.1 Prepare certificates for TheGreenBow vpn client 3.1x... 10 3.2 Phase 1 configuration.... 10 3.3 Phase 2 configuration.... 13
VPN IPSec Troubleshooting.... 15 4.1 PAYLOAD MALFORMED error.... 15 4.2 INVALID COOKIE error.... 15 4.3 no keystate error.... 15 4.4 received remote ID other than expected error... 15 4.5 NO PROPOSAL CHOSEN error... 16 4.6 INVALID ID INFORMATION error.... 16 4.7 I clicked on Open tunnel, but nothing happens... 16 4.8 The VPN tunnel is up but I cant ping !.... 16 Contacts..... 18
Doc.Ref Doc.version VPN version
tgbvpn_ug_ZyWALL35_en 1.0 Sept.2006 3.2

1. Introduction

1.1 Goal of this document
This configuration guide describes how to configure TheGreenBow IPSec VPN Client with a ZyXEL ZyWALL 35 firmware 4.01 using certificates. Well be using ZyWALL built in Certification Authority.

1.2 VPN Network topology

In our VPN network example (diagram hereafter), we will connect TheGreenBow IPSec VPN Client to the LAN behind the ZyXEL firewall. The VPN client is connected to the Internet with a DSL connection or from a LAN. All the addresses in this document are given for example purpose. A Road Warrior connection also needs to be configured. The following example makes use of these values: External IP of the ZyWALL: LAN mygateway.dyndns.org (or public IP address) 192.168.1.0/255.255.255.0
IPSec VPN Client (Remote)
mygateway.dyndns.org 192.168.1.1

192.168.1.9

Internet

ZyWALL 35

192.168.1.78 IPSec VPN Client (as seen on the LAN)

2 Setup ZyWALL35

2.1 Prepare ZyWALLs built in Certification Authority
Root certificate is created the first time the ZyWALL is powered on. This is an automatic process. Go to Security menu, then Certificates to obtain this screen:
Press Create to configure a host to net ipsec connection
2.2 Create a Roadwarrior certificate
Enter the certificate name, and choose the subject informations type : email or ip address or host domain name In this example we chose to use email adress
Choose the enrollment options. In our example, we are using ZyWALL built in certifications authority, therefore create a self-signed certificate must be selected. Press Apply. Once the certificate creation process is done, the main certificate screen shows:
For later use we need now to export both root and roadwarrior certificates in PKCS12 format. Click on export icons to go to this screen:
Choose PKCS#12, and enter a password. DO THIS FOR BOTH CERTIFICATES. Add p12 extension on the popup window, or rename certificates after they have been saved.

2.3 Create a Roadwarrior vpn tunnel
Go to VPN tab and click the add gateway policy button :
In Gateway Policy Informations, the wan address (My Address) is a private subnet address. Replace it by a static wan public address if you have one, or enter a dynamic dns name in My Domain Name. In Authentication Key select the roadwarrior certificate previously created. Local ID will be automatically defined from the certificate created. In our example it is email address. Remote ID: choose a type from the drop down menu and enter a value. It can be setup to any. But to increase security, choose subject name and in the value field, copy and paste the subject of roadwarrior certificate (you can find it on certificates page)
To increase security, Extended Authentication can be used by entering a user name and password. In this case the vpn client should be configured accordingly in phase1 advanced by checking x-auth popup OR entering a username and password (login and pwd are sent automatically without any popup). In IKE Proposal, choose algorithms (for firmware 4.01, AES and SHA1 are the best choice). The longest key that can be chosen is DH2 (1024 bits). Press Apply to save settings and return to vpn main screen:
A network policy linked to this gateway policy must be added. Press the add network policy button
Check Allow Netbios Broadcast to be able to browse distant network. In Local Network, define either a single ip address, either an address range or a subnet address, depending on what machine(s) you wish to access through vpn. In this example, a subnet was defined. In Remote Network, leave single address setting with 0.0.0.0, meaning any address for the client. If you specify an address here, the vpn client must be set up accordingly, as the router will only accept requests from the address entered. Choose algorithms and pfs (perfect forward secrecy) settings. Press Apply, the Zywall 35 is now configured.
3 Setup TheGreenBow VPN client 3.1x
3.1 Prepare certificates for TheGreenBow vpn client 3.1x
Transfer both previously created PKCS#12 certificates (on floppy disk or usb stick, or email, or direct copy) to the nomad pc initiator of the vpn tunnel. Use our tool here: http://www.thegreenbow.fr/bin/tgbvpn_certificates.zip to convert them into pem which is the usable certificate format for our vpn client. Once the conversion is done 4 files are created for EACH certificate. rootCA.pem clientcert.pem Der_asn1_DN.txt Local.key Both conversions will provide same names. Make sure to distinguish Certification Authority pem files from Roadwarrior pem files (by creating 2 folders for example). This will avoid messing with them when importing to the vpn client.
3.2 Phase 1 Configuration
Right click on Configuration in TheGreenbow VPN client and select New Phase 1. Phase 1 settings should match the gateway policy on the ZyXEL. Choose a name for your connection to ZyWALL and enter the remote gateway which is the WAN IP address of the ZyXEL, or its dynamic dns name if it has been defined. Select certificate box and press certificates import

IPSec VPN Router Configuration Property of TheGreenBow Sistech SA - Sistech 2001-2006 10/18
Press browse for each certificate and go to the locations where pem files were saved previously. Make sure you select the correct certificate between Certification authority folder and client (roadwarrior) folder.
Root certificate file is clientCert.pem from the certification authority folder (dont select rootCA.pem) User certificate file is clientCert.pem from the client folder User private key file is local.key from the client folder Make sure all 3 are imported (showing a small key in before each name) and press OK to go back to main screen of the client. Choose P1 advanced:
Local ID must be defined as DER ASN1 DN type. Copy the content of the file Der_asn1_dn.txt located in the client folder, and copy it in the value field. Nothing is needed in Remote ID. Press OK
3.3 Phase 2 Configuration
Create a phase2: right-click on phase1 and select add phase 2 Phase 2 settings should match network policy of the ZyWALL.
Modify Address type by choosing subnet address, and add the remote lan address and mask (must match what was defined on ZyWALL) Algorithms, pfs and dh group must match ZyWALLs settings. The VPN client address must not belong to the remote subnet range. In our example, we chose 0.0.0.0 meaning the vpn client address is the physical address of the machine either dynamically assigned by isp or lan dhcp. (from a hotel for example)
If the roadwarrior tries to connect from a lan which address is 192.168.1.0, the vpn connection wont establish correctly. In this case you must specify an ip address in another range (10.0.0.1 for example, or 192.168.0.1 or any private ip address you wish taken from another ip range than the lan behind the router) Phase2 advanced is used to enter alternate dns and/or wins servers addresses from the ones the vpn client is using prior to establish the tunnel.
Successful console log for this vpn connection:
4 VPN IPSec Troubleshooting
4.1 PAYLOAD MALFORMED error
114920 Default (SA CNXVPN1-P1) SEND phase 1 Main Mode [SA][VID] 114920 Default (SA CNXVPN1-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

If you have an PAYLOAD MALFORMED error you might have a wrong Phase 1 [SA], check if the encryption algorithms are the same on each side of the VPN tunnel.

4.2 INVALID COOKIE error

115933 Default message_recv: invalid cookie(s) 5918ca0c2634288f 7364e3e486eDefault dropped message from 195.100.205.114 port 500 due to notification type INVALID_COOKIE 115933 Default SEND Informational [NOTIFY] with 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.

4.3 no keystate error

Default Default Default Default Default Default (SA CNXVPN1-P1) SEND phase 1 Main Mode [SA][VID] (SA CNXVPN1-P1) RECV phase 1 Main Mode [SA][VID] (SA CNXVPN1-P1) SEND phase 1 Main Mode [KEY][NONCE] (SA CNXVPN1-P1) RECV phase 1 Main Mode [KEY][NONCE] (SA CNXVPN1-P1) SEND phase 1 Main Mode [ID][HASH][NOTIFY] ipsec_get_keystate: no keystate in ISAKMP SA 00B57C50
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.
4.4 received remote ID other than expected error
120348 Default (SA CNXVPN1-P1) SEND phase 1 Main 120349 Default (SA CNXVPN1-P1) RECV phase 1 Main 120349 Default (SA CNXVPN1-P1) SEND phase 1 Main 120351 Default (SA CNXVPN1-P1) RECV phase 1 Main 120351 Default (SA CNXVPN1-P1) SEND phase 1 Main 120351 Default (SA CNXVPN1-P1) RECV phase 1 Main 120351 Default ike_phase_1_recv_ID: received support@thegreenbow.fr Mode [SA][VID] Mode [SA][VID] Mode [KEY][NONCE] Mode [KEY][NONCE] Mode [ID][HASH][NOTIFY] Mode [ID][HASH][NOTIFY] remote ID other than

expected

The Remote ID value (see Advanced Button) does not match what the remote endpoint is expected.
4.5 NO PROPOSAL CHOSEN error
115911 Default (SA CNXVPN1-P1) SEND phase 1 Main Mode [SA][VID] 115913 Default (SA CNXVPN1-P1) RECV phase 1 Main Mode [SA][VID] 115913 Default (SA CNXVPN1-P1) SEND phase 1 Main Mode [KEY][NONCE] 115915 Default (SA CNXVPN1-P1) RECV phase 1 Main Mode [KEY][NONCE] 115915 Default (SA CNXVPN1-P1) SEND phase 1 Main Mode [ID][HASH][NOTIFY] 115915 Default (SA CNXVPN1-P1) RECV phase 1 Main Mode [ID][HASH][NOTIFY] 115915 Default phase 1 done: initiator id c364cd70: 195.100.205.112, responder id c364cd72: 195.100.205.114, src: 195.100.205.112 dst: 195.100.205.Default (SA CNXVPN1-CNXVPN1-P2) SEND phase 2 Quick Mode [SA][KEY][ID][HASH][NONCE] 115915 Default RECV Informational [HASH][NOTIFY] with NO_PROPOSAL_CHOSEN error 115915 Default RECV Informational [HASH][DEL] 115915 Default CNXVPN1-P1 deleted

If you have an NO PROPOSAL CHOSEN error, check that the Phase 2 encryption algorithms are the same on each side of the VPN Tunnel. Check Phase 1 algorithms if you have this:
115911 Default (SA CNXVPN1-P1) SEND phase 1 Main Mode [SA][VID] 115911 Default RECV Informational [NOTIFY] with NO_PROPOSAL_CHOSEN error
4.6 INVALID ID INFORMATION error
122623 Default (SA CNXVPN1-P1) SEND phase 1 Main Mode [SA][VID] 122625 Default (SA CNXVPN1-P1) RECV phase 1 Main Mode [SA][VID] 122625 Default (SA CNXVPN1-P1) SEND phase 1 Main Mode [KEY][NONCE] 122626 Default (SA CNXVPN1-P1) RECV phase 1 Main Mode [KEY][NONCE] 122626 Default (SA CNXVPN1-P1) SEND phase 1 Main Mode [ID][HASH][NOTIFY] 122626 Default (SA CNXVPN1-P1) RECV phase 1 Main Mode [ID][HASH][NOTIFY] 122626 Default phase 1 done: initiator id c364cd70: 195.100.205.112, responder id c364cd72: 195.100.205.114, src: 195.100.205.112 dst: 195.100.205.Default (SA CNXVPN1-CNXVPN1-P2) SEND phase 2 Quick Mode [SA][KEY][ID][HASH][NONCE] 122626 Default RECV Informational [HASH][NOTIFY] with INVALID_ID_INFORMATION error 122626 Default RECV Informational [HASH][DEL] 122626 Default CNXVPN1-P1 deleted
If you have an INVALID ID INFORMATION error, check if Phase 2 ID (local address and network address) is correct and match what is expected by the remote endpoint. Check also ID type (Subnet address and Single address). If network mask is not check, you are using a IPV4_ADDR type (and not a IPV4_SUBNET type).
4.7 I clicked on Open tunnel, but nothing happens.
Read logs of each VPN tunnel endpoint. IKE requests can be dropped by firewalls. An IPSec Client uses UDP port 500, UDP port 4500 and protocol ESP (protocol 50).
4.8 The VPN tunnel is up but I cant ping !
If the VPN tunnel is up, but you still cannot ping the remote LAN, here are a few guidelines: Check Phase 2 settings: VPN Client address and Remote LAN address. Usually, VPN Client IP address should not belong to the remote LAN subnet Once VPN 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
IPSec VPN Router Configuration Property of TheGreenBow Sistech SA - Sistech 2001-2006 16/18
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 a no Default gateway setting. You cannot access to the computers in the LAN by their name. You must specify their IP address inside the LAN. We recommend you to install ethereal (http://www.ethereal.com) on one of your target computer. You can check that your pings arrive inside the LAN.

5 Contacts

News and updates on TheGreenBow web site : http://www.thegreenbow.com Technical support by email at support@thegreenbow.com Sales contacts at +ou by email at info@thegreenbow.com