Configuration Guide User guide

376 FastIron Configuration Guide
53-1002494-02
IPv6 over IPv4 tunnels
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 Figure 32, these tunnels encapsulate an IPv6 packet within an IPv4 packet.
FIGURE 32 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 365.
IPv6 over IPv4 tunnel configuration notes
• This feature is not supported in a mixed hardware configuration with 48-port 10/100/1000
Mbps Ethernet POE (SX-FI48GPP) interface modules, together with IPv4 or IPv6 interface
modules, or management modules with user ports.
NOTE
If the 48-port 10/100/1000 Mbps Ethernet POE (SX-FI48GPP) interface module is
inadvertently inserted in a system that has IPv4 or IPv6 interface modules, or a management
module with user ports, existing tunnels will be taken down immediately. To recover, physically
remove the module that caused the mix-and-match condition and then disable and re-enable
the tunnel interfaces.
• 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.
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