Split Tunnel and Cisco AnyConnect

cisco-anyconnectsplit-tunnelvpn

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

Best Answer

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.