How many bits are available for group IDs in an IPv6 Multicast IP address?

How many bits are available for group IDs in an IPv6 Multicast IP address?


A. 65
B. 96
C. 112
D. 128

Correct Answer: C
Explanation/Reference:
Explanation:
The format of the multicast address defines several scopes and types of addresses using the 4-bit fields Flag and Scope. These fields are located after the FF::/8 prefix. Finally, the low-order 112-bit of the multicast address is the multicast group ID.

http://ptgmedia.pearsoncmg.com/images/chap02_1587050862/elementLinks/02fig15.gif Reference: http://www.ciscopress.com/articles/article.asp?p=31948&seqNum=2