Hi Customer (name blocked for privacy),
In regards to setting up a VPN you need to have identical settings on the Symantec appliance and on the computer vpn client configuration that you are using to vpn in with.
Which basically since your ISP is providing you with a DHCP address every time your IP changes you will have to update the client configuration on the client side.
You would set it up with the 241.xx.xx.xx as far as the IP and every other setting must be identical for this to work and be able to communicate successfully.
I would recommend contacting your ISP in regards to issuing you out a Static IP address.
I will be honest i am not an expert in VPN configurations but i spoke to out System Engineer at work in regards to your issue and he is very knowledgable in regards to the configuration setup and this is what he has informed me. If you have any furthur questions in regards to the configuration i will do my best to assist you.
Thanks
If you are satisfied with my Answer please click the GREEN ACCEPT BUTTON,This is the only way I am paid for assisting you. BONUSES and POSITIVE FEEDBACK are greatly appreciated