It hasn't been updated for awhile but still is a good checklist!
Router Security Configuration Guide
Principles and guidance for secure configuration of IP routers, with detailed instructions for Cisco Systems routers
Router Security Guidance Activity of the System and Network Attack Center (SNAC)
December 15, 2005 Version: 1.1c
See also
Router Security Configuration Guide Supplement - Security for IPv6 Routers, Version 1.0
All the reports should be hosted at Cisco Router Guides
