© 2006 Cisco Systems, Inc. All rights
reserved.
Cisco Confidential
Presentation_ID
15
IPv6 Prefixes &
Address Space Usage
§All
IPv6 Subscriber prefixes are automatically generated from IPv4
No DHCPv6, ND, etc. to deploy or operate
When the IPv4 address changes, so does the IPv6 prefix
§Must
carefully select which 6rd IPv6 Prefix you are going to use,
number of 6rd Domains, etc.
§If
6rd was deployed by all AS holders in the world today, using the
most “inefficient” encoding described in the document, 6rd would
consume a /9.
This is a “worst-case” scenario (see Section 10 for more
details)