I have a 506e running several tunnels to a number of 501's. I tried to add\na new 501 but, try as I can, I can't seem to build the new tunnel. I am\nusing script exactly the same as the other units but I continually get the\nMM_KEY_EXCH error on both units. It remains for a minute or two and then\ndeletes itself.\n\nObvisouly the two units are communicating but can't seem to complete the\ntunnel (phase 2?).\n\nWe have redone the ISAKMP key many times. And have run out of ideas. What\nusually causes this kind of problem? I would really appreciate suggestions\nwhere I can go from here?