Ipv4 Over Ipv4 Tunnel - H3C S9500 Series Operation Manual

Operation Manual – Tunneling
H3C S9500 Series Routing Switches
V. Tunnel hybrid insertion
In practice, many cards only support IPv4. However, a tunnel can only be established
over IPv6 cards. After tunnel packets arrive on the destination node, it is very likely that
an IPv4 card received the packets. The tunnel hybrid insertion function enables IPv4
cards to support the tunnel termination. Through the function, tunnel packets can be
terminated without obstruction on the destination node. This function is implemented by
configuring an ACL on incoming interfaces of IPv4 cards to redirect tunnel packets to
IPv6 cards.
Caution:
In the case of tunnel hybrid insertion, the outbound interface of tunnel packets must
support IPv6 if expedite termination is enabled. Otherwise, tunnel packets cannot be
decapsulated.

1.1.2 IPv4 over IPv4 Tunnel

I. Introduction to IPv4 over IPv4 tunneling protocol
IPv4 over IPv4 tunneling protocol (RFC 1853) is developed for IP data packet
encapsulation so that data can be transferred from one IPv4 network to another IPv4
network.
II. Encapsulation and decapsulation
Packets to be transferred through a tunnel undergo an encapsulation process and
decapsulation process.
IPv 4 header IPv4 data
IPv4 network
IPv 4 host
Figure 1-4 Principle of IPv4 over IPv4 tunnel
Figure 1-4 shows these two processes.
IPv 4 header IPv 4 header IPv4 data
IPv 4 network
IPv4 tunnel
Router A
1-7
Chapter 1 Tunneling Configuration
IPv4 header IPv 4 data
IPv 4 network
Router B
IPv 4 host