Brocade ICX 6650 Administration Guide 121
53-1002600-01
IPv6 over IPv4 tunnels 5
IPv6 over IPv4 tunnels
NOTE
This feature is supported only with the IPv6 Layer 3 PROM and the full Layer 3 image.
To enable communication between isolated IPv6 domains using the IPv4 infrastructure, you can
manually configure IPv6 over IPv4 tunnels that provide static point-point connectivity.
As shown in Figure10, these tunnels encapsulate an IPv6 packet within an IPv4 packet.
FIGURE 10 IPv6 over an IPv4 tunnel
In general, a manually configured tunnel establishes a permanent link between switches in IPv6
domains. A manually configured tunnel has explicitly configured IPv4 addresses for the tunnel
source and destination.
This tunneling mechanism requires that the Layer 3 switch at each end of the tunnel run both IPv4
and IPv6 protocol stacks. The Layer 3 switches running both protocol stacks, or dual-stack routers,
can interoperate directly with both IPv4 and IPv6 end systems and routers. Refer to “Configuring
IPv4 and IPv6 protocol stacks” on page 111.

IPv6 over IPv4 tunnel configuration notes

The local tunnel configuration must include both source and destination addresses.
The remote side of the tunnel must have the opposite source/destination pair.
A tunnel interface supports static and dynamic IPv6 configuration settings and routing
protocols.
Duplicate Address Detection (DAD) is not currently supported with IPv6 tunnels. Make sure
tunnel endpoints do not have duplicate IP addresses.
Neighbor Discovery (ND) is not supported with IPv6 tunnels.
If a tunnel source port is a multi-homed IPv4 source, the tunnel will use the first IPv4 address
only. For proper tunnel operation, use the ip address option.

Configuring a manual IPv6 tunnel

You can use a manually configured tunnel to connect two isolated IPv6 domains. You should deploy
this point-to-point tunnelling mechanism if you need a permanent and stable connection.
To configure a manual IPv6 tunnel, enter commands such as the following on a Layer 3 Switch
running both IPv4 and IPv6 protocol stacks on each end of the tunnel.
IPv4 Header IPv6 Header IPv6 Data IPv6 Header IPv6 Data
IPv6 Header IPv6 Data
Dual-Stack L3 Switch
IPv6 Traffic Over IPv4 Tunnel
IPv6
Network
IPv6
Network
IPv4
Network
Dual-Stack L3 Switch IPv6 Host
IPv6 Host