Ipv4 Over Ipv4 Tunneling - HP 10500 Series Configuration Manual

Figure 67 Principle of 6to4 tunneling
ISATAP tunneling
3.
An ISATAP tunnel is a point-to-point automatic tunnel. It provides a solution to connect an IPv6 host
to an IPv6 network over an IPv4 network.
The destination addresses of IPv6 packets and the IPv6 addresses of tunnel interfaces are all ISATP
addresses. The ISATAP address format is prefix(64bit):0:5EFE:ip-address. The 64-bit prefix is a
valid IPv6 unicast address prefix, ip-address is a 32-bit IPv4 address in the format of abcd or
abcd:efgh, which identifies the tunnel destination and need not be globally unique.
ISATAP tunnels are mainly used for communication between IPv6 routers or between an IPv6 host
and an IPv6 router over an IPv4 network.
Figure 68 Principle of ISATAP tunneling

IPv4 over IPv4 tunneling

IPv4 over IPv4 tunneling (RFC 1853) enables isolated IPv4 networks to communicate with each other over
another IPv4 network. For example, an IPv4 over IPv4 tunnel can connect isolated private IPv4 networks
over a public IPv4 network.
Figure 69 Principle of IPv4 over IPv4 tunneling
Packets traveling through a tunnel undergo encapsulation and de-encapsulation, as shown in
• Encapsulation:
Device A receives an IP packet from an IPv4 host and submits it to the IP protocol stack.
a.
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Figure 69.