I am trying to configure my client using VPN (strongswan) to access the remote server whose DNS is vpngw.fh-kempten.de

Details of my remote VPN Server are: Authentication Method = Mutual +XAuth PSK =****

Phase 1 Exchange Type = aggressive DH exchange = group2 Cipher Algorithm = 3ds Hash Algorithm = md5 Key life time limit = 28800secs

Phase 2 Tensform Algorithm = esp-3des HMAC Algorithm = md5 PFC exchange = Auto compress Algorithm = disabled Key life time limit = 28800secs


Host Name or IP = vpngw.fh-kempten.de port = 500 Auto configuration = IKE conf. pull MTU = 1400 Adapter mode = use a virtual adapter and assigned address

Client firewall options NAT traversal = enable NAT traversal port = 4500 Keep alive packet rate = 15s IKE fragmentation = enable Maximum packet siye = 540 bytes

This is all info I have related to my VPN Server which is a remote server.

Using the command sudo ipsec up ikev1-psk-xauth, I try to run my client VPN. I get the following error in my raspberry pi

initiating Aggressive Mode IKE_SA ikev1-psk-xauth[1] to
generating AGGRESSIVE request 0 [ SA KE No ID V V V V V ]
sending packet: from[500] to[500] (363 bytes)
received packet: from[500] to[500] (404 bytes)
parsed AGGRESSIVE response 0 [ SA KE No ID HASH V V V NAT-D NAT-D V V ]
received Cisco Unity vendor ID
received XAuth vendor ID
received draft-ietf-ipsec-nat-t-ike-02\n vendor ID
received FRAGMENTATION vendor ID
received unknown vendor ID: 1f:07:f7:0e:aa:65:14:d3:b0:fa:96:54:2a:50:01:00
IDir '' does not match to 'vpngw.fh-kempten.de'
generating INFORMATIONAL_V1 request 304912695 [ N(INVAL_ID) ]
sending packet: from[500] to[500] (56 bytes)
establishing connection 'ikev1-psk-xauth' failed

Following is my ipsec.conf file

config setup
conn ikev1-psk-xauth
ike = 3des-md5-modp1024!
esp = 3des-md5-modp1024!
modeconfig = pull
aggressive = yes
#keyexchange = ikev2
authby = secret
type = transport
leftauth = psk
leftauth2 = xauth
right = vpngw.fh-kempten.de
rightauth = psk
rightauth2 = xauth
auto = add

My motivation is to access the shared drives which are present on the remote VPN server. Any suggestions would be highly appreciated. Thanks in advance!!


The remote identity the server returns does not match your configuration (the identities default to the IP addresses). Try configuring rightid = vpngw.fh-kempten.de and you might have to configure leftid to the group name (Cisco lingo), which you have to determine somehow.

For your information, using Aggressive Mode with XAauth/PSK is inherently unsafe and the algorithm selection is from a different era (so is the use of L2TP actually), so you might want to complain to the admins of your university for providing such a crappy VPN.

  • After yout possible recommendation. I changed my config file and commenting agressive gives me the following when I run sudo ipsec up ikev1-psk-xauth – Saqib Shakeel Mar 8 '19 at 9:25
  • parsed TRANSACTION request 36532437 [ HASH CPS(X_STATUS) ] no XAuth method found – Saqib Shakeel Mar 8 '19 at 9:28
  • Sounds like the xauth-generic plugin is not loaded. See here. – ecdsa Mar 8 '19 at 12:43
  • I have tried to install and use ** xauth-generic ** plugin but when I try to install using this command <!-- sudo apt-get install strongswan strongswan-plugin-xauth-generic--> , it gives me the following lines Reading package lists... Done Building dependency tree Reading state information... Done E: Unable to locate package strongswan-plugin-xauth-generic – Saqib Shakeel Mar 13 '19 at 20:47
  • Individual packages for plugins were only available on older Ubuntu releases. On newer ones the plugin is in the libcharon-standard-plugins package. – ecdsa Mar 14 '19 at 7:39

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