System Administration Guide: IP Services

6to4relay Command

6to4 tunneling enables communication between isolated 6to4 sites. However, to transfer packets with a native, non-6to4 IPv6 site, the 6to4 router must establish a tunnel with a 6to4 relay router. The 6to4 relay router then forwards the 6to4 packets to the IPv6 network and ultimately, to the native IPv6 site. If your 6to4-enabled site must exchange data with a native IPv6 site, you use the 6to4relay command to enable the appropriate tunnel.

Because the use of relay routers is insecure, tunneling to a relay router is disabled by default in Oracle Solaris. Carefully consider the issues that are involved in creating a tunnel to a 6to4 relay router before deploying this scenario. For detailed information on 6to4 relay routers, refer to Considerations for Tunnels to a 6to4 Relay Router. If you decide to enable 6to4 relay router support, you can find the related procedures in How to Configure a 6to4 Tunnel.

Syntax of 6to4relay

The 6to4relay command has the following syntax:

6to4relay -e [-a IPv4-address] -d -h

Enables support for tunnels between the 6to4 router and an anycast 6to4 relay router. The tunnel endpoint address is then set to, the default address for the anycast group of 6to4 relay routers.

-a IPv4-address

Enables support for tunnels between the 6to4 router and a 6to4 relay router with the specified IPv4-address.


Disables support for tunneling to the 6to4 relay router, the default for Oracle Solaris.


Displays help for 6to4relay.

For more information, refer to the 6to4relay(1M) man page.

Example 11–3 Default Status Display of 6to4 Relay Router Support

The 6to4relay command, without arguments, shows the current status of 6to4 relay router support. This example shows the default for the Oracle Solaris implementation of IPv6.

# /usr/sbin/6to4relay
6to4relay:6to4 Relay Router communication support is disabled

Example 11–4 Status Display With 6to4 Relay Router Support Enabled

If relay router support is enabled, 6to4relay displays the following output:

# /usr/sbin/6to4relay
6to4relay:6to4 Relay Router communication support is enabled
IPv4 destination address of Relay Router=

Example 11–5 Status Display With a 6to4 Relay Router Specified

If you specify the -a option and an IPv4 address to the 6to4relay command, the IPv4 address that you give with -a is displayed instead of

6to4relay does not report successful execution of the -d, -e, and-a IPv4 address options. However, 6to4relay does display any error messages that might be generated when you run these options.