Ipv6 Over Ipv4 Gre Tunnels; Auto 6To4 Tunneling; Standards Compliance - Nortel Secure 4134 Configuration

The host or router at each end of a configured tunnel must support both
the IPv4 and IPv6 protocol stacks. Manually configured tunnels can be
configured between border routers or between a border router and a host.
The entry tunnel end point (the encapsulating node) encapsulates the
IPv6 packet with an IPv4 header with the configured IPv4 tunnel source
and tunnel destination IP addresses. The exit tunnel end point (the
de-capsulating node) removes the outer IPv4 header and forward or
consume the received IPv6 packet.

IPv6 over IPv4 GRE tunnels

IPv6 traffic can be carried over IPv4 Generic Route Encapsulation
(GRE) tunnels using the standard GRE tunneling technique. As in IPv6
manually-configured tunnels, GRE tunnels are links between two points, with
a separate tunnel for each link. The tunnels carry IPv6 as the passenger
protocol with GRE as the carrier protocol and IPv4 as the transport protocol.
GRE has a protocol field that identifies the passenger protocol.
The entry tunnel end point (the encapsulating node) encapsulates the IPv6
packet with a GRE-IPv4 header using the configured IPv4 tunnel source and
tunnel destination IP addresses. The exit tunnel end point removes the outer
GRE-IPv4 header and processes or forwards the received IPv6 packet.

Auto 6to4 tunneling

Auto 6to4 tunneling is a dynamic way to deploy tunnels between sites made
up of IPv6 nodes. Tunneling of IPv6 packets is done dynamically, using the
destination IPv6 address of a packet originating from the IPv6 node. Auto
6to4 encapsulates the IPv6 packet in IPv4 and uses the IPv4 routing domain.
The destination IP address of the tunnel does not need to be manually
preset. The IPv4 address embedded in the 2002:: /16 prefixed destination
IPv6 address is used to find the other end of the automatic tunnel.
The key difference between automatic 6to4 tunnels and manually-configured
tunnels is that the tunnel is not point-to-point; rather, it is point-to-multipoint.
6to4 prefixes use the 2002:: /16 address space assigned by IANA. A globally
unicast IPv4 assigned to the 6to4 router is converted to hexadecimal and
appended to the 2002:: /16 prefix.
Routing protocols are not supported on auto 6to4 tunnels.

Standards compliance

The SR4134 implementation of GRE and IPIP tunneling complies with the
following RFCs:
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Copyright © 2007, Nortel Networks
.
RFC 1853, IP in IP Tunneling
Nortel Secure Router 4134
Security — Configuration and Management
NN47263-600 01.02 Standard
10.0 3 August 2007
Standards compliance 67