Cisco IOS Access Lists: Help for Network Administrators
Hardening Cisco Routers (O'Reilly Networking)
Cisco IOS Cookbook: Field-Tested Solutions to Cisco Router Problems (Cookbooks (O'Reilly))
Network Warrior: Everything You Need to Know That Wasn't on the CCNA Exam
OSPF: Anatomy of an Internet Routing Protocol
Internet Routing Architectures (Design & Implementation)
Cisco BGP-4 Command and Configuration Handbook
Routing TCP/IP, Volume 1 (2nd Edition)
MPLS for Cisco Networks: A CCIE v5 guide to Multiprotocol Label Switching (Cisco CCIE Routing and Switching v5.0) (Volume 2)
Cisco LAN Switching (CCIE Professional Development series)