When I took written , I used CCIE Written simulation tool from Netmaster Class (www.netmasterclass.com)
but seems like they have discontinued the product.
On the flip side, INE released updated version of CCIE R&S Written bootcamp couple of months back.
But older version had Practice simulation. Chances are pretty high that if you buy current version, you get access to older version too. But still check with them before you buy.
Oops You were looking for CCIE Sec written. Here you go:
Awesome thanks man. I wouldn't have even thought to check them out. Ucertify also has one, but I've never used any of their testing engines before. Have you used INE or ucertify for anything?