Recommended Study Resources
The CCIE R&S written exam is a natural progression for candidates who have experience in routing and switching or have it as part of the job role. Going through CCNA and CCNP in R&S also would help.
Passing the CCIE R&S written exam will renew any other CCIE track certification you may have.
I recommend the following study references:
- CCIE Routing and Switching Certification Guide, 4th edition by Wendell Odom, Rus Healy, and Denise Donohue
- Routing TCP/IP, Volume 1 , 2nd Edition by Jeff Doyle and Jennifer Carroll
- Routing TCP/IP, Volume 2 , 2nd Edition by Jeff Doyle and Jennifer Carroll
Additionally, I recommend you explore the following:
- The CCIE R&S online resources and go through the Switching section
- The Certification Ask the Expert forum discussions
- CCIE Routing and Switching Study Group