A client recently changed internet service providers and since the change was unable to connect with the Cisco VPN Client from their computers. The are an accounting practices, using MYOB and the Cisco VPN Client to perform ELS lodgement of tax returns.
We suspected at first it might be the ISP blocking certain traffic but found it was the Netcomm NB604n modem/router that the ISP had provided. Before the Cisco VPN Client would work (and other VPN clients according to the documentation) you need to add some “port trigger” information.
A step by step document of the process can be downloaded from Netcomm here.