If you’re getting a:
HTTP: processing GET URL ‘/admin/public/index.html’ from host error from the browser. These are the steps the check.
First run: show flash
You should see the asdm image there.
If you don’t, you’ll need to use tftp and grab the image from another ASA or from Cisco if you have a service contract. Make sure it works with the compatibility matrix: http://www.cisco.com/en/US/docs/security/asa/compatibility/asamatrx.html
Enable mode: en
Configure terminal: config t
make sure the current configuration makes sense: show run http (This is an access list)
enable the server: http server enable
Designate the ASDM image file: asdm image [location of asdm image file]
Write to memory: wr m
If that doesn’t work the following might help: ssl encryption aes256-sha1 aes128-sha1 3des-sha1