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Operation Manual – GRE
H3C S9500 Series Routing Switches
Chapter 1 GRE Configuration
1-7
remote end. Or, you can enable the dynamic routing protocol on both the tunnel
interface and the router interface connecting the private network so that the
dynamic routing protocol can establish a routing entry that allows the tunnel to
forward packets through the tunnel.
z
IPv6 over IPv4 GRE tunnel interfaces support such dynamic routing protocols as
OSPFv3, RIPng and BGP4+.
z
To run dynamic routing protocols (apart from BGP4+) on a tunnel interface, you
need to enable the expediting function on the relevant tunnel first.
z
It is not allowed to set up on a tunnel interface static routes whose destination
addresses are in the network segment as that tunnel interface.
z
For GRE IPv6 over IPv4 packets, due to restrictions of match conditions for the
expediting function, only the physical ports with the link type as Access or Hybrid
can be bound to the VLAN interface that acts as the source interface of a tunnel.
Moreover, when the link type of a port is Hybrid, the
untagged
attribute must be
specified for the VLAN that sends GRE tunnel packets.
z
The XP4DB, GV48DA and GV48DB boards do not support the expediting function
on GRE IPv6 over IPv4 tunnels.
1.3 Displaying and Maintaining GRE
To do…
Use the command…
Remarks
Display information about
a specified or all tunnel
interfaces
display interface tunnel
[
number
]
Available in any view
Display IPv6 information
about a tunnel interface
display ipv6 interface
tunnel
number
Available in any view
1.4 GRE Tunnel Configuration Examples
1.4.1 GRE IPv4 over IPv4 Tunnel Configuration Example
I. Network requirements
Switch A and Switch B are interconnected through an IPv4 network. Two private IPv4
subnets Group1 and Group2 are interconnected through a GRE tunnel between the
two switches.