Introduction To Tunneling - 3Com MSR 50 Series Configuration Manual

49
Introduction to
Tunneling
T
UNNELING
When configuring tunneling, go to these sections for information you are
interested in:
"Introduction to Tunneling" on page 693
■
"Tunneling Configuration Task List" on page 700
■
"Configuring an IPv6 Manually Configured Tunnel" on page 700
■
"Configuring Automatic IPv4-Compatible IPv6 Tunnel" on page 704
■
"Configuring 6to4 Tunnel" on page 708
■
"Configuring ISATAP Tunnel" on page 714
■
"Configuring IPv4 over IPv4 Tunnel" on page 717
■
"Configuring IPv4 over IPv6 Tunnel" on page 721
■
"Configuring IPv6 over IPv6 Tunnel" on page 725
■
"Displaying and Maintaining Tunneling Configuration" on page 730
■
"Troubleshooting Tunneling Configuration" on page 730
■
n
A tunnel interface number is in the X format, where X ranges from 0 to 1023.
The expansion of Internet results in scarce IPv4 addresses. Although the
technologies such as temporary IPv4 address allocation and network address
translation (NAT) relieve the problem of IPv4 address shortage to some extent, they
not only increase the overhead in address resolution and processing, but also lead
to high-level application failures. Furthermore, they will still face the problem that
IPv4 addresses will eventually be used up. Internet protocol version 6 (IPv6)
adopting the 128-bit addressing scheme completely solves the above problem.
Since significant improvements have been made in address space, security,
network management, mobility, and QoS, IPv6 becomes one of the core standards
for the next generation Internet protocol. IPv6 is compatible with all protocols
except IPv4 in the TCP/IP suite. Therefore, IPv6 can completely take the place of
IPv4.
Before IPv6 becomes the dominant protocol, the network using the IPv6 protocol
stack is expected to communicate with the Internet using IPv4. Therefore, an
IPv6-IPv4 interworking technology must be developed to ensure the smooth
transition from IPv4 to IPv6. In addition, the interworking technology should
provide efficient, seamless information transfer. The Internet Engineering Task
Force (IETF) set up the next generation transition (NGTRANS) working group to
study problems about IPv4-to-IPv6 transition and efficient, seamless IPv4-IPv6
interworking. Currently, multiple transition technologies and interworking
C
ONFIGURATION