Ipip; Gre; Tunnel Protection; Ipv6 Over Ipv4 Tunneling - Nortel Secure 4134 Configuration

66 GRE and IPIP tunneling fundamentals
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In addition, GRE tunnels support the following additional features:
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IPIP

IP in IP encapsulation differs from GRE in that it does not insert its own
special glue header between IP headers. Instead, the original IP Header is
retained, and simply wrapped in another standard IP header

GRE

Generic Routing Encapsulation (GRE) is a standards-based (RFC1701,
RFC2784) tunneling protocol that can encapsulate a wide variety of protocol
packet types inside IP tunnels, creating a virtual point-to-point link between
routers at remote points over an IP network. A tunnel is a logical interface
that provides a way to encapsulate passenger packets inside a transport
protocol. By connecting multiprotocol subnetworks in a single-protocol
backbone environment, IP tunneling using GRE allows network expansion
across a single-protocol backbone environment. GRE tunnels can be used
for unencrypted traffic.

Tunnel protection

IPsec transport mode is used to provide protection for packets that already
encapsulated (or tunneled) using other protocols. Both IPIP and GRE
can operate with IPsec to provide tunnel protection. IPsec can be used in
transport mode with these protocols and it can provide security for these
packets using ESP and/or AH.
The SR4134 only supports tunnel protection for IPv4 tunnels.

IPv6 over IPv4 tunneling

IPv6 over manually-configured IPv4 tunnels
A manually configured IPv6 over IPv4 tunnel is equivalent to a permanent
link between two IPv6 domains over an IPv4 backbone. An IPv6 address is
manually configured on a tunnel interface, and manually configured IPv4
addresses are assigned to the tunnel source and the tunnel destination.
Copyright © 2007, Nortel Networks
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configurable TOS parameter: TOS bits from the inner (passenger) IP
header are copied to the outer (transport) IP header. This allows the
QOS DiffServ technology to operate on intermediate routers between
GRE tunnel endpoints. Additionally the TOS bits are configurable
routing protocols: can be enabled on the tunnel interface.
multicast routing protocols: can be enabled on the tunnel interface.
tunnel keepalive: sends keepalive packets to keep track of the tunnel
end points and take down the line protocol of the GRE tunnel interface if
the far end becomes unreachable
optional data sequencing: dropping of out of order data grams
Nortel Secure Router 4134
Security — Configuration and Management
NN47263-600 01.02 Standard
10.0 3 August 2007