6TO4RELAY(8) Maintenance 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)