Cisco VPN client

vpnc is Cisco VPN client for Linux. I always use it to connect to my company at home. However, I found that I couldn't connect on one day. After checking, it was because I have updated the Ubuntu vpnc package. The new config file need to add a "NAT Traversal Mode cisco-udp":

...
IPSec gateway
IPSec ID
IPSec secret
Xauth username
Xauth password

NAT Traversal Mode cisco-udp
...

After added the list line, everything is okay again :>