I have several subnets connected via RVS4000 routers. Network assistant shows all of the devices fine but will not show the link between the subnets. For example:
I have a subnet with three 3560 switches and the links between these switches is displayed but the link to that subnet is not. It seems that the RVS4000 is blocking something that allows the link to be displayed.
It may simply be case of it being a "Linksys by Cisco" device with no CDP support, which CNA probably relies on for the link-graphing function. Besides, I don't see RVS4000 on the Supported Devices list of CNA: http://www.cisco.com/en/US/prod/collateral/netmgtsw/ps6504/ps5931/product_data_sheet0900aecd8068820a.html