6TO4RELAY(8) Maintenance Commands and Procedures 6TO4RELAY(8)

NAME

6to4relay - administer configuration for 6to4 relay router
communication

SYNOPSIS

/usr/sbin/6to4relay


/usr/sbin/6to4relay [-e] [-a addr]


/usr/sbin/6to4relay [-d]


/usr/sbin/6to4relay [-h]

DESCRIPTION

The 6to4relay command is used to configure 6to4 relay router
communication. Relay router communication support is enabled by
setting the value of a variable that stores an IPv4 address within
the tun module. This variable is global to all tunnels and defines
the policy for communication with relay routers. By default, the
address is set to INADDR_ANY (0.0.0.0), and the kernel interprets the
value to indicate that support for relay router communication is
disabled. Otherwise, support is enabled, and the specified address is
used as the IPv4 destination address when packets destined for native
IPv6 (non-6to4) hosts are sent through the 6to4 tunnel interface. The
6to4relay command uses a project private ioctl to set the variable.


6to4relay used without any options outputs the current, in-kernel,
configuration status. Use the -a option to send packets to a specific
relay router's unicast address instead of the default anycast
address. The address specified with the -a option does not specify
the policy for receiving traffic from relay routers. The source relay
router on a received packet is non-deterministic, since a different
relay router may be chosen for each sending native IPv6 end-point.


Configuration changes made by using the 6to4relay are not persistent
across reboot. The changes will persist in the kernel only until you
take the tunnel down

OPTIONS

The 6to4relay command supports the following options:

-a addr
Use the specified address, addr.


-e
Enable support for relay router. Use -a addr if it is
specified. Otherwise, use the default anycast address,
192.88.99.1.


-d
Disable support for the relay router.


-h
Help

OPERANDS

The following operands are supported:

addr
A specific relay router's unicast address. addr must be
specified as a dotted decimal representation of an IPv4
address. Otherwise, an error will occur, and the command will
fail.

EXAMPLES

Example 1: Printing the In-Kernel Configuration Status

Use /usr/sbin/6to4relay without any options to print the in-kernel
configuration status.


example# /usr/sbin/6to4relay


If 6to4 relay router communication is disabled, the administrator
will see the following message:


6to4relay: 6to4 Relay Router communication support is disabled.


If 6to4 router communication is enabled, the user will see this
message:

6to4relay: 6to4 Relay Router communication support is enabled.
IPv4 destination address of Relay Router = 192.88.99.1

EXIT STATUS

The following exit values are returned:

0
Successful completion.


>0
An error occurred.

FILES

/usr/sbin/6to4relay
The default installation root

SEE ALSO

attributes(7), ifconfig(8)


Huitema, C. RFC 3068, An Anycast Prefix for 6to4 Relay Routers.
Network Working Group. June, 2001.


Carpenter, B. and Moore, K. RFC 3056, Connection of IPv6 Domains via
IPv4 Clouds. Network Working Group. February, 2001.

DIAGNOSTICS

The 6to4relay reports the following messages:

6to4relay: input (0.0.0.0) is not a valid IPv4 unicast address


Example:


The following example provides an incorrect unicast address.

example# 6to4relay -e -a 0.0.0.0

Description:


The address specified with the -a option must be a valid unicast
address.


6to4relay: option requires an argument -a
usage:
6to4relay
6to4relay -e [-a <addr>]
6to4relay -d
6to4relay -h


Example:


The following example does not include an argument for the -a
option.

example# 6to4relay -e -a

Description:


The -a option requires an argument.


usage:
6to4relay
6to4relay -e [-a <addr>]
6to4relay -d
6to4relay -h


Example:


The following example specifies options that are not permitted.

example# 6to4relay -e -d

Description:


The options specified are not permitted. A usage message is
output to the screen.


usage:
6to4relay
6to4relay -e [-a <addr>]
6to4relay -d
6to4relay -h


Example:


The following example specifies the -a option without specifying
the -e option.

example# 6to4relay -a 1.2.3.4

Description:


The -e option is required in conjunction with the -a option. A
usage message is output to the screen.


6to4relay: ioctl (I_STR) : Invalid argument


Example:


The following example specifies an invalid address.

example# 6to4relay -e -a 239.255.255.255

Description:


The address specified with the -a option must not be a class d
addr.


November 19, 2002 6TO4RELAY(8)