vpn - Split Tunnel and Cisco AnyConnect

27
2013-10
  • Nathan

    I am using Cisco AnyConnect Secure Mobility Client 3.1.02026 on Windows 7 64-bit. I have heard there is a checkbox which enables split tunneling. However, this checkbox is removed from the GUI probably due to the administrator's settings. The administrator doesn't want to make any configuration changes. I would like to force split tunneling. How? It's okay if the solution uses a different VPN client. The solution can not make any changes on the VPN server. I have tried a virtual machine and it works, but I would like a more convenient solution. I have tried messing around with route table but I failed probably due to lack of knowing how to do it right.

    Here is my route print before connecting to the VPN.

    ===========================================================================
Interface List
 14...00 1e 4f d7 64 5b ......Intel(R) 82566DM-2 Gigabit Network Connection
  1...........................Software Loopback Interface 1
 25...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter
 27...00 00 00 00 00 00 00 e0 Teredo Tunneling Pseudo-Interface
===========================================================================

IPv4 Route Table
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0      192.168.1.1      192.168.1.3     10
        127.0.0.0        255.0.0.0         On-link         127.0.0.1    306
        127.0.0.1  255.255.255.255         On-link         127.0.0.1    306
  127.255.255.255  255.255.255.255         On-link         127.0.0.1    306
      169.254.0.0      255.255.0.0         On-link       192.168.1.3     11
  169.254.255.255  255.255.255.255         On-link       192.168.1.3    266
      192.168.1.0    255.255.255.0         On-link       192.168.1.3    266
      192.168.1.3  255.255.255.255         On-link       192.168.1.3    266
    192.168.1.255  255.255.255.255         On-link       192.168.1.3    266
        224.0.0.0        240.0.0.0         On-link         127.0.0.1    306
        224.0.0.0        240.0.0.0         On-link       192.168.1.3    266
  255.255.255.255  255.255.255.255         On-link         127.0.0.1    306
  255.255.255.255  255.255.255.255         On-link       192.168.1.3    266
===========================================================================
Persistent Routes:
  Network Address          Netmask  Gateway Address  Metric
      169.254.0.0      255.255.0.0      192.168.1.3       1
          0.0.0.0          0.0.0.0     10.154.128.1       1
===========================================================================

IPv6 Route Table
===========================================================================
Active Routes:
 If Metric Network Destination      Gateway
 27     58 ::/0                     On-link
  1    306 ::1/128                  On-link
 27     58 2001::/32                On-link
 27    306 2001:0:5ef5:79fd:3431:3b25:b736:1859/128
                                    On-link
 14    266 fe80::/64                On-link
 27    306 fe80::/64                On-link
 27    306 fe80::3431:3b25:b736:1859/128
                                    On-link
 14    266 fe80::3933:bb6f:892:d161/128
                                    On-link
  1    306 ff00::/8                 On-link
 27    306 ff00::/8                 On-link
 14    266 ff00::/8                 On-link
===========================================================================
Persistent Routes:
  None

    Here is my route print after connecting to the VPN.

    ===========================================================================
Interface List
 19...00 05 9a 3c 7a 00 ......Cisco AnyConnect Secure Mobility Client Virtual Miniport Adapter for Windows x64
 14...00 1e 4f d7 64 5b ......Intel(R) 82566DM-2 Gigabit Network Connection
  1...........................Software Loopback Interface 1
 25...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter
 27...00 00 00 00 00 00 00 e0 Teredo Tunneling Pseudo-Interface
167...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #3
===========================================================================

IPv4 Route Table
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0      192.168.1.1      192.168.1.3     10
          0.0.0.0          0.0.0.0     10.154.128.1     10.154.159.8      2
     10.154.128.0    255.255.224.0         On-link      10.154.159.8    257
     10.154.159.8  255.255.255.255         On-link      10.154.159.8    257
   10.154.159.255  255.255.255.255         On-link      10.154.159.8    257
        127.0.0.0        255.0.0.0         On-link         127.0.0.1    306
        127.0.0.1  255.255.255.255         On-link         127.0.0.1    306
  127.255.255.255  255.255.255.255         On-link         127.0.0.1    306
     137.254.4.91  255.255.255.255      192.168.1.1      192.168.1.3     11
      169.254.0.0      255.255.0.0         On-link      10.154.159.8    306
      169.254.0.0      255.255.0.0         On-link       192.168.1.3    306
  169.254.255.255  255.255.255.255         On-link      10.154.159.8    257
  169.254.255.255  255.255.255.255         On-link       192.168.1.3    266
      192.168.1.1  255.255.255.255         On-link       192.168.1.3     11
      192.168.1.3  255.255.255.255         On-link       192.168.1.3    266
        224.0.0.0        240.0.0.0         On-link         127.0.0.1    306
        224.0.0.0        240.0.0.0         On-link       192.168.1.3    266
        224.0.0.0        240.0.0.0         On-link      10.154.159.8    257
  255.255.255.255  255.255.255.255         On-link         127.0.0.1    306
  255.255.255.255  255.255.255.255         On-link       192.168.1.3    266
  255.255.255.255  255.255.255.255         On-link      10.154.159.8    257
===========================================================================
Persistent Routes:
  Network Address          Netmask  Gateway Address  Metric
      169.254.0.0      255.255.0.0      192.168.1.3       1
          0.0.0.0          0.0.0.0     10.154.128.1       1
===========================================================================

IPv6 Route Table
===========================================================================
Active Routes:
 If Metric Network Destination      Gateway
 19     11 ::/0                     On-link
  1    306 ::1/128                  On-link
 19    266 fe80::/64                On-link
 19    266 fe80::2a78:5341:7450:2bc1/128
                                    On-link
 14    266 fe80::3933:bb6f:892:d161/128
                                    On-link
 19    266 fe80::c12f:601f:cdf:4304/128
                                    On-link
 19    266 fe80::c5c3:8e03:b9dd:7df5/128
                                    On-link
  1    306 ff00::/8                 On-link
 14    266 ff00::/8                 On-link
===========================================================================
Persistent Routes:
  None
    • Answers
  • ubiquibacon

    First understand that the reason your network admins have disallowed split tunneling is because it potentially allows any malicious person/code to circumvent the security measures that have been implemented by accessing the network via your computer. Believe me I know not having a split tunnel is annoying, but ask your self is it worth the risk?

    Now that warnings are out of the way I can tell you Cisco AnyConnect prevents a split tunnel by temporarily re-writing the routing table of the host computer. Use route print before you start AnyConnect and use it again after to see the differences. You can write a script to adjust the routing table and run it after you start AnyConnect. An easier solution that probably doesn't violate your networks usage policy is simply using a VM with AnyConnect. Your host's NIC doesn't get locked down and you don't break any rules... best of both worlds.


    • Related Question

    Configuring Windows VPN Connection from Cisco AnyConnect
  • Oliver Hanappi

    I don't know if it is possible but I would like to configure a Windows 7 VPN connection in a way that I can connect to a network which I normally reach by using Cisco AnyConnect VPN Client. Does Cisco use a protocol which Windows 7 understands also and where can I find the configuration details of the VPN connection?

    If you wonder why I'm trying to do this: I need to connect via VPN to several different networks from different companies/organizations/universities and each one uses its own VPN client. I don't want my computer to have 5 VPN clients installed, therefore I'm trying to replace them with simple Windows VPN connections.


    • Related Answers
  • Joey

    That greatly depends on the configuration of the server. Cisco Concentrators can speak PPTP which works on nearly every version of Windows, but it's costly in terms of performance. The number of possible connections drops to about a tenth for the server so this is rarely activated.

    Furthermore there seems to be an option to enable L2TP. The documentation states that but at least for our university here no one figured out how to enable it and set it up.

    You would have to ask the person maintaining the server whether one of the above options apply.

    For the "usual" Cisco IPSec over UDP there is no native option in Windows, unfortunately.