1-1 
1  IPv6 Configuration 
When configuring IPv6, go to these sections for information you are interested in: 
z  IPv6 Overview 
z  IPv6 Configuration Task List 
z  IPv6 Configuration Example 
 
 
z  The term “router” in this document refers to a router in a generic sense or an Ethernet switch 
running a routing protocol. 
z  3com Switch 4200G supports IPv6 management features, but do not support IPv6 forwarding and 
related features.  
 
IPv6 Overview 
Internet Protocol Version 6 (IPv6), also called IP next generation (IPng), was designed by the Internet 
Engineering Task Force (IETF) as the successor to Internet Protocol Version 4 (IPv4). The significant 
difference between IPv6 and IPv4 is that IPv6 increases the IP address size from 32 bits to 128 bits.  
IPv6 Features 
Header format simplification 
IPv6 cuts down some IPv4 header fields or moves them to extension headers to reduce the overhead of 
the basic IPv6 header. IPv6 uses a fixed-length header, thus making IPv6 packet handling simple and 
improving the forwarding efficiency. Although the IPv6 address size is four times that of IPv4 addresses, 
the size of the IPv6 header is only twice that of the IPv4 header (excluding the Options field). For the 
specific IPv6 header format, see 
Figure 1-1.