Lan to Lan tunnel DLink DFL-700 - Cisco 2821

[Netmav]

Hi.

I'm trying to set up a IPsec tunnel between a DLink DFL-700 Firewall and a Cisco 2821.
It just won't work. We have tried so many different thing, that I can't even remember all of them! I'm new to this kind of setup, so I'm really out of ideas now..

Have anyone tried this before? Is there anything special with any of these "boxes", that I need to know about?

I'm a little desperate, as I can't get it to work.

Any help is greatly appreciated.

Thanks.

Regards, Martin