R3303-HP HSR6800 Routers Layer 3 - IP Services Configuration Guide

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Configuring tunneling

Overview

Tunneling is an encapsulation technology. One network protocol encapsulates packets of another

network protocol and transfers them over a virtual point-to-point connection. The virtual connection is

called a tunnel. Packets are encapsulated at the tunnel source end and de-encapsulated at the tunnel

destination end. Tunneling refers to the whole process from data encapsulation to data transfer to data

de-encapsulation.

Tunneling supports the following technologies:

• Transition techniques, such as IPv6 over IPv4 tunneling, to interconnect IPv4 and IPv6 networks.

• Virtual Private Network (VPN) such as IPv4 over IPv4 tunneling, IPv4/IPv6 over IPv6 tunneling,

Generic Routing Encapsulation (GRE), Dynamic Virtual Private Network (DVPN), and IPsec

tunneling.

• Traffic engineering, such as Multiprotocol Label Switching traffic engineering (MPLS TE) to prevent

network congestion.

Unless otherwise specified, the term tunnel in this document refers to IPv6 over IPv4, IPv4 over IPv4, IPv4

over IPv6, and IPv6 over IPv6 tunnels.

For more information about GRE, see "Configuring GRE."

For more information about DVPN, see "Configuring DVPN."

For more information about IPsec, see Security Configuration Guide.

For more information about MPLS TE, see MPLS Configuration Guide.

IPv6 over IPv4 tunneling

Implementation

IPv6 over IPv4 tunneling adds an IPv4 header to IPv6 packets so that IPv6 packets can pass an IPv4

network through a tunnel to realize interworking between isolated IPv6 networks, as shown in Figure 93.

he devices at the ends of an IPv6 over IPv4 tunnel must support the IPv4/IPv6 dual stack.