3.4.a Implement and troubleshoot RIPv2

The Cisco implementation of RIPv2 supports cleartext and Message Digest 5 (MD5) authentication, route summarization, classless inter-domain routing (CIDR), and variable-length subnet masks (VLSMs) over RIPv1.

Adam, Paul (2014-07-12). All-in-One CCIE V5 Written Exam Guide (Kindle Locations 2958-2960).  . Kindle Edition.

http://www.ciscopress.com/articles/article.asp?p=102174&seqNum=4

http://blog.ine.com/2010/04/15/how-basic-are-rip-timers-test-your-knowledge-now/