Provided by: vpnc_0.5.3+git20220927-1build2_amd64 bug

NAME

       vpnc - client for Cisco VPN3000 Concentrator, IOS and PIX

SYNOPSIS

       vpnc [--version] [--print-config] [--help] [--long-help] [options] [config files]

DESCRIPTION

       This manual page documents briefly the vpnc and vpnc-disconnect commands.

       vpnc  is  a  VPN  client  for  the  Cisco  3000 VPN  Concentrator,  creating  a IPSec-like
       connection as a tunneling network device for the local system. It uses the TUN/TAP  driver
       in   Linux   kernel   2.4  and  above  and device tun(4) on BSD. The created connection is
       presented as a tunneling network device to the local system.

       OBLIGATORY WARNING: the most used configuration (XAUTH authentication with pre-shared keys
       and  password  authentication)  is  insecure by design, be aware of this fact when you use
       vpnc to exchange sensitive data like passwords!

       The vpnc daemon by itself does not set any routes, but it calls  vpnc-script  to  do  this
       job.  vpnc-script  displays  a connect banner. If the concentrator supplies a network list
       for split-tunneling these networks are added to the routing table.  Otherwise the default-
       route  will  be modified to point to the tunnel.  Further a host route to the concentrator
       is added in the later case.  If the client host needs DHCP, care  must  be  taken  to  add
       another host route to the DHCP-Server around the tunnel.

       The vpnc-disconnect command is used to terminate the connection previously created by vpnc
       and restore the previous routing configuration.

CONFIGURATION

       The daemon reads configuration data from the following places:
       •      command line options
       •      config file(s) specified on the command line
       •      /etc/vpnc/default.conf
       •      /etc/vpnc.conf
       •      prompting the user if not found above

       vpnc can parse options and configuration files in any order. However the  first  place  to
       set  an option wins.  configuration filenames which do not contain a / will be searched at
       /etc/vpnc/<filename>   and   /etc/vpnc/<filename>.conf.     Otherwise    <filename>    and
       <filename>.conf  will  be used.  If no configuration file is specified on the command-line
       at all, both /etc/vpnc/default.conf and /etc/vpnc.conf will be loaded.

       Additionally, if the configuration file "-" is specified on  the  command-line  vpnc  will
       read  configuration  from  stdin.  The configuration is parsed and the connection proceeds
       when stdin is closed or the special character CEOT (CTRL-D) is read.

OPTIONS

       The program options can be either given as arguments (but not all  of  them  for  security
       reasons) or be stored in a configuration file.

       --gateway <ip/hostname>
              IP/name of your IPSec gateway
       conf-variable: IPSec gateway <ip/hostname>

       --id <ASCII string>
              your group name
       conf-variable: IPSec ID <ASCII string>

       --secret <ASCII string>
              your group password (cleartext)
       conf-variable: IPSec secret <ASCII string>

       (configfile only option)
              your group password (obfuscated)
       conf-variable: IPSec obfuscated secret <hex string>

       --username <ASCII string>
              your username
       conf-variable: Xauth username <ASCII string>

       --password <ASCII string>
              your password (cleartext)
       conf-variable: Xauth password <ASCII string>

       (configfile only option)
              your password (obfuscated)
       conf-variable: Xauth obfuscated password <hex string>

       --domain <ASCII string>
              (NT-) Domain name for authentication
       conf-variable: Domain <ASCII string>

       --xauth-inter
              enable interactive extended authentication (for challenge response auth)
       conf-variable: Xauth interactive

       --vendor <cisco/netscreen/fortigate>
              vendor of your IPSec gateway
              Default: cisco
       conf-variable: Vendor <cisco/netscreen/fortigate>

       --natt-mode <natt/none/force-natt/cisco-udp>
              Which NAT-Traversal Method to use:
              •      natt -- NAT-T as defined in RFC3947
              •      none -- disable use of any NAT-T method
              •      force-natt  -- always use NAT-T encapsulation even without presence of a NAT
                     device (useful if the OS captures all ESP traffic)
              •      cisco-udp -- Cisco proprietary UDP encapsulation, commonly over Port 10000
              Note: cisco-tcp encapsulation is not yet supported
              Default: natt
       conf-variable: NAT Traversal Mode <natt/none/force-natt/cisco-udp>

       --script <command>
              command is executed using system() to configure the interface, routing and  so  on.
              Device  name,  IP,  etc.  are  passed using environment variables, see README. This
              script is executed right after ISAKMP is done, but before tunneling is enabled.  It
              is called when vpnc terminates, too
              Default: /usr/share/vpnc-scripts/vpnc-script
       conf-variable: Script <command>

       --dh <dh1/dh2/dh5/dh14/dh15/dh16/dh17/dh18>
              name of the IKE DH Group
              Default: dh2
       conf-variable: IKE DH Group <dh1/dh2/dh5/dh14/dh15/dh16/dh17/dh18>

       --pfs <nopfs/dh1/dh2/dh5/dh14/dh15/dh16/dh17/dh18/server>
              Diffie-Hellman group to use for PFS
              Default: server
       conf-variable: Perfect Forward Secrecy <nopfs/dh1/dh2/dh5/dh14/dh15/dh16/dh17/dh18/server>

       --enable-1des
              Deprecated: Please use --enable-weak-encryption instead.
       conf-variable: Enable Single DES

       --enable-weak-encryption
              enables weak encryption methods (such as DES, 3DES)
       conf-variable: Enable weak encryption

       --enable-no-encryption
              enables using no encryption for data traffic (key exchanged must be encrypted)
       conf-variable: Enable no encryption

       --enable-weak-authentication
              enables weak authentication methods (such as MD5)
       conf-variable: Enable weak authentication

       --application-version <ASCII string>
              Application Version to report. Note: Default string is generated at runtime.
              Default: Cisco Systems VPN Client 0.5.3+git20220927-1build2:Linux
       conf-variable: Application version <ASCII string>

       --ifname <ASCII string>
              visible name of the TUN/TAP interface
       conf-variable: Interface name <ASCII string>

       --ifmode <tun/tap>
              mode of TUN/TAP interface:
              •      tun: virtual point to point interface (default)
              •      tap: virtual ethernet interface
              Default: tun
       conf-variable: Interface mode <tun/tap>

       --ifmtu <0-65535>
              Set MTU for TUN/TAP interface (default 0 == automatic detect)
       conf-variable: Interface MTU <0-65535>

       --debug <0/1/2/3/99>
              Show verbose debug messages
              •
                      0: Do not print debug information.
              •
                      1: Print minimal debug information.
              •
                      2: Show statemachine and packet/payload type information.
              •
                      3: Dump everything excluding authentication data.
              •      99: Dump everything INCLUDING AUTHENTICATION data (e.g. PASSWORDS).
       conf-variable: Debug <0/1/2/3/99>

       --no-detach
              Don't detach from the console after login
       conf-variable: No Detach

       --pid-file <filename>
              store the pid of background process in <filename>
              Default: /run/vpnc.pid
       conf-variable: Pidfile <filename>

       --local-addr <ip/hostname>
              local IP to use for ISAKMP / ESP / ... (0.0.0.0 == automatically assign)
              Default: 0.0.0.0
       conf-variable: Local Addr <ip/hostname>

       --local-port <0-65535>
              local ISAKMP port number to use (0 == use random port)
              Default: 500
       conf-variable: Local Port <0-65535>

       --udp-port <0-65535>
              Local  UDP  port  number  to  use (0 == use random port).  This is only relevant if
              cisco-udp nat-traversal is used.  This is the _local_ port, the remote udp port  is
              discovered automatically.  It is especially not the cisco-tcp port.
              Default: 10000
       conf-variable: Cisco UDP Encapsulation Port <0-65535>

       --dpd-idle <0,10-86400>
              Send  DPD packet after not receiving anything for <idle> seconds.  Use 0 to disable
              DPD completely (both ways).
              Default: 300
       conf-variable: DPD idle timeout (our side) <0,10-86400>

       --non-inter
              Don't ask anything, exit on missing options
       conf-variable: Noninteractive

       --auth-mode <psk/cert/hybrid>
              Authentication mode:
              •      psk:    pre-shared key (default)
              •      cert:   server + client certificate (not implemented yet)
              •      hybrid: server certificate + xauth (if built with openssl support)
              Default: psk
       conf-variable: IKE Authmode <psk/cert/hybrid>

       --ca-file <filename>
              filename and path to the CA-PEM-File
       conf-variable: CA-File <filename>

       --ca-dir <directory>
              path of the trusted CA-Directory
              Default: /etc/ssl/certs
       conf-variable: CA-Dir <directory>

       --target-network <target network/netmask>
              Target network in dotted decimal or CIDR notation
              Default: 0.0.0.0/0.0.0.0
       conf-variable: IPSEC target network <target network/netmask>

       --password-helper <executable>
              path to password program or helper name
       conf-variable: Password helper <executable>

       --print-config
              Prints your configuration; output can be used as vpnc.conf

FILES

       /etc/vpnc.conf /etc/vpnc/default.conf
              The default configuration file. You can specify the same config directives as  with
              command  line  options  and  additionally  IPSec  secret  and  Xauth  password both
              supplying a cleartext password. Scrambled passwords from  the  Cisco  configuration
              profiles can be used with IPSec obfuscated secret and Xauth obfuscated password.

              See EXAMPLES for further details.

       /etc/vpnc/*.conf
              vpnc will read configuration files in this directory when the config filename (with
              or without .conf) is specified on the command line.

EXAMPLES

       This is an example vpnc.conf with pre-shared keys:

              IPSec gateway vpn.example.com
              IPSec ID ExampleVpnPSK
              IKE Authmode psk
              IPSec secret PskS3cret!
              Xauth username user@example.com
              Xauth password USecr3t

       And another one with hybrid authentication (requires that  vpnc  was  built  with  openssl
       support):

              IPSec gateway vpn.example.com
              IPSec ID ExampleVpnHybrid
              IKE Authmode hybrid
              CA-Dir /etc/vpnc
              or
              CA-File /etc/vpnc/vpn-example-com.pem
              IPSec secret HybS3cret?
              Xauth username user@example.com
              Xauth password 123456

       The  lines  begin with a keyword (no leading spaces!).  The values start exactly one space
       after the keywords, and run to the end of line. This  lets  you  put  any  kind  of  weird
       character (except CR, LF and NUL) in your strings, but it does mean you can't add comments
       after a string, or spaces before them.

       In case the the CA-Dir option is used, your certificate needs to be named  something  like
       722d15bd.X,  where  X is a manually assigned number to make sure that files with colliding
       hashes have different names. The number can be derived from the certificate file itself:

       openssl x509 -subject_hash -noout -in /etc/vpnc/vpn-example-com.pem

       See also the --print-config option to generate a config file, and the example file in  the
       package documentation directory where more advanced usage is demonstrated.

       Advanced   features   like   manual  setting  of  multiple  target  routes  and  disabling
       /etc/resolv.conf rewriting is documented in the README of the vpnc package.

AUTHOR

       This man-page has been written by Eduard Bloch <blade(at)debian.org> and Christian  Lackas
       <delta(at)lackas.net>, based on vpnc README by Maurice Massar <vpnc(at)unix-ag.uni-kl.de>.
       Permission is granted to copy, distribute and/or modify this document under the  terms  of
       the GNU General Public License, Version 2 any later version published by the Free Software
       Foundation.

       On Debian systems, the complete text of the GNU General Public License  can  be  found  in
       /usr/share/common-licenses/GPL.

SEE ALSO

       pcf2vpnc(1),         cisco-decrypt(1),         ip(8),        ifconfig(8),        route(1),
       http://www.unix-ag.uni-kl.de/~massar/vpnc/