Tunneling; Introduction To Tunneling - 3Com Switch 4800G 24-Port Configuration Manual

40
Introduction to

Tunneling

IPv6 over IPv4 Tunnel
T
UNNELING
When configuring tunneling, go to these sections for information you are
interested in:
"Introduction to Tunneling" on page 523
■
"Tunneling Configuration Task List" on page 526
■
"Configuring IPv6 Manual Tunnel" on page 526
■
"Configuring 6to4 Tunnel" on page 530
■
"Configuring ISATAP Tunnel" on page 535
■
"Displaying and Maintaining Tunneling Configuration" on page 538
■
"Troubleshooting Tunneling Configuration" on page 538
■
Tunneling is an encapsulation technology, which utilizes one network transport
protocol to encapsulate packets of another network transport protocol and
transfer them over the network. A tunnel is a virtual point-to-point connection. In
practice, the virtual interface that supports only point-to-point connections is
called tunnel interface. One tunnel provides one channel to transfer encapsulated
packets. Packets can be encapsulated and decapsulated at both ends of a tunnel.
Tunneling refers to the whole process from data encapsulation to data transfer to
data decapsulation.
n
NTP-related commands are available in tunnel interface view on 3Com Switch
4800G Family, but NTP features cannot be enabled after you execute the NTP
commands. For related information about NTP, refer to "NTP Configuration" on
page 947.
Principle
The IPv6 over IPv4 tunneling mechanism encapsulates an IPv4 header in IPv6 data
packets so that IPv6 packets can pass an IPv4 network through a tunnel to realize
interworking between isolated IPv6 networks, as shown in Figure 157.
c
CAUTION: The devices at both ends of an IPv6 over IPv4 tunnel must support
IPv4/IPv6 dual stack.
C
ONFIGURATION