try adding the following two lines to the end of your DMZ ACLaccess-list dmz-in extended deny ip 10.0.0.0 255.0.0.0 10.0.0.0 255.0.0.0access-list dmz-in extended permit ip any any
You just want to force the speed say to 10 or 100 MB? interface Ethernet0/1 speed 100 duplex fullor from the ASDM click CONFIGURATION - INTERFACES select a interface to modify - CONFIGURE HARDWARE PROPERTIES.
I think the original poster was asking how do you track the vpn logons through the appliance so he knows who is logging in when and what accounts are no longer active. Some ideas would be to use Cisco ACS to track the activity or Syslog.