System Administration Guide: IP Services

IPv6-Related Commands

This section describes commands that are added with the Oracle Solaris IPv6 implementation. The text also describes modifications to existing commands to support IPv6.

ipaddrsel Command

The ipaddrsel command enables you to modify the IPv6 default address selection policy table.

The Oracle Solaris kernel uses the IPv6 default address selection policy table to perform destination address ordering and source address selection for an IPv6 packet header. The /etc/inet/ipaddrsel.conf file contains the policy table.

The following table lists the default address formats and their priorities for the policy table. You can find technical details for IPv6 address selection in the inet6(7P) man page.

Table 11–5 IPv6 Address Selection Policy Table

Prefix 

Precedence 

Definition 

::1/128

50 

Loopback 

::/0

40 

Default 

2002::/16

30 

6to4 

::/96

20 

IPv4 Compatible 

::ffff:0:0/96

10 

IPv4 

In this table, IPv6 prefixes (::1/128 and ::/0) take precedence over 6to4 addresses (2002::/16) and IPv4 addresses (::/96 and ::ffff:0:0/96). Therefore, by default, the kernel selects the global IPv6 address of the interface for packets going to another IPv6 destination. The IPv4 address of the interface has a lower priority, particularly for packets going to an IPv6 destination. Given the selected IPv6 source address, the kernel also uses the IPv6 format for the destination address.

Reasons for Modifying the IPv6 Address Selection Policy Table

Under most instances, you do not need to change the IPv6 default address selection policy table. If you do need to administer the policy table, you use the ipaddrsel command.

You might want to modify the policy table under the following circumstances:

For details about the ipaddrsel command, refer to the ipaddrsel(1M) man page.

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
-e

Enables support for tunnels between the 6to4 router and an anycast 6to4 relay router. The tunnel endpoint address is then set to 192.88.99.1, 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.

-d

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

-h

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=192.88.99.1


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 192.88.99.1.

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.


ifconfig Command Extensions for IPv6 Support

The ifconfig command enables IPv6 interfaces and the tunneling module to be plumbed. ifconfig uses an extended set of ioctls to configure both IPv4 and IPv6 network interfaces. The following describes ifconfig options that support IPv6 operations. See Monitoring the Interface Configuration With the ifconfig Command for a range of both IPv4 and IPv6 tasks that involve ifconfig.

index

Sets the interface index.

tsrc/tdst

Sets the tunnel source or destination.

addif

Creates the next available logical interface.

removeif

Deletes a logical interface with a specific IP address.

destination

Sets the point-to-point destination address for an interface.

set

Sets an address, netmask, or both for an interface.

subnet

Sets the subnet address of an interface.

xmit/-xmit

Enables or disables packet transmission on an interface.

Chapter 7, Configuring an IPv6 Network (Tasks) provides IPv6 configuration procedures.


Example 11–6 Adding a Logical IPv6 Interface With the -addif Option of the ifconfig Command

The following form of the ifconfig command creates the hme0:3 logical interface:


# ifconfig hme0 inet6 addif up
Created new logical interface hme0:3

This form of ifconfig verifies the creation of the new interface:


# ifconfig hme0:3 inet6
hme0:3: flags=2000841<UP,RUNNING,MULTICAST,IPv6> mtu 1500 index 2
		inet6  inet6 fe80::203:baff:fe11:b321/10


Example 11–7 Removing a Logical IPv6 Interface With the -removeif Option of the ifconfig Command

The following form of the ifconfig command removes the hme0:3 logical interface.


# ifconfig hme0:3 inet6 down

# ifconfig hme0 inet6 removeif 1234::5678


Example 11–8 Using ifconfig to Configure an IPv6 Tunnel Source


# ifconfig ip.tun0 inet6 plumb index 13

Opens the tunnel to be associated with the physical interface name.


# ifconfig ip.tun0 inet6
ip.tun0: flags=2200850<POINTOPOINT,RUNNING,MULTICAST,NONUD,
#IPv6> mtu 1480 index 13
		inet tunnel src 0.0.0.0 
		inet6 fe80::/10 --> :: 

Configures the streams that are needed for TCP/IP to use the tunnel device and report the status of the device.


# ifconfig ip.tun0 inet6 tsrc 120.46.86.158 tdst 120.46.86.122

Configures the source and the destination address for the tunnel.


# ifconfig ip.tun0 inet6
ip.tun0: flags=2200850<POINTOPOINT,RUNNING,MULTICAST,NONUD,
IPv6> mtu 1480 index 13
		inet tunnel src 120.46.86.158  tunnel dst 120.46.86.122
		inet6 fe80::8192:569e/10 --> fe80::8192:567a

Reports the new status of the device after the configuration.



Example 11–9 Configuring a 6to4 Tunnel Through ifconfig (Long Form)

This example of a 6to4 pseudo-interface configuration uses the subnet ID of 1 and specifies the host ID, in hexadecimal form.


# ifconfig ip.6to4tun0 inet6 plumb
# ifconfig ip.6to4tun0 inet tsrc 129.146.86.187 \
2002:8192:56bb:1::8192:56bb/64 up

# ifconfig ip.6to4tun0 inet6
ip.6to4tun0: flags=2200041<UP,RUNNING,NONUD,IPv6>mtu 1480 index 11
        inet tunnel src 129.146.86.187 
        tunnel hop limit 60 
        inet6 2002:8192:56bb:1::8192:56bb/64 


Example 11–10 Configuring a 6to4 Tunnel Through ifconfig (Short Form)

This example shows the short form for configuring a 6to4 tunnel.


# ifconfig ip.6to4tun0 inet6 plumb
# ifconfig ip.6to4tun0 inet tsrc 129.146.86.187 up

# ifconfig ip.6to4tun0 inet6
ip.6to4tun0: flags=2200041<UP,RUNNING,NONUD,IPv6>mtu 1480 index 11
        inet tunnel src 129.146.86.187 
        tunnel hop limit 60 
        inet6 2002:8192:56bb::1/64 

netstat Command Modifications for IPv6 Support

The netstat command displays both IPv4 and IPv6 network status. You can choose which protocol information to display by setting the DEFAULT_IP value in the /etc/default/inet_type file or by using the -f command-line option. With a permanent setting of DEFAULT_IP, you can ensure that netstat displays only IPv4 information. You can override this setting by using the -f option. For more information on the inet_type file, see the inet_type(4) man page.

The -p option of the netstat command displays the net-to-media table, which is the ARP table for IPv4 and the neighbor cache for IPv6. See the netstat(1M) man page for details. See How to Display the Status of Sockets for descriptions of procedures that use this command.

snoop Command Modifications for IPv6 Support

The snoop command can capture both IPv4 and IPv6 packets. This command can display IPv6 headers, IPv6 extension headers, ICMPv6 headers, and Neighbor Discovery protocol data. By default, the snoop command displays both IPv4 and IPv6 packets. If you specify the ip or ip6 protocol keyword, the snoop command displays only IPv4 or IPv6 packets. The IPv6 filter option enables you to filter through all packets, both IPv4 and IPv6, displaying only the IPv6 packets. See the snoop(1M) man page for details. See How to Monitor IPv6 Network Traffic for procedures that use the snoop command.

route Command Modifications for IPv6 Support

The route command operates on both IPv4 and IPv6 routes, with IPv4 routes as the default. If you use the -inet6 option on the command line immediately after the route command, operations are performed on IPv6 routes. See the route(1M) man page for details.

ping Command Modifications for IPv6 Support

The ping command can use both IPv4 and IPv6 protocols to probe target hosts. Protocol selection depends on the addresses that are returned by the name server for the specific target host. By default, if the name server returns an IPv6 address for the target host, the ping command uses the IPv6 protocol. If the server returns only an IPv4 address, the ping command uses the IPv4 protocol. You can override this action by using the -A command-line option to specify which protocol to use.

For detailed information, see the ping(1M) man page. For procedures that use ping, refer to Probing Remote Hosts With the ping Command.

traceroute Command Modifications for IPv6 Support

You can use the traceroute command to trace both the IPv4 and IPv6 routes to a specific host. From a protocol perspective, traceroute uses the same algorithm as ping. Use the -A command-line option to override this selection. You can trace each individual route to every address of a multihomed host by using the -a command-line option.

For detailed information, see the traceroute(1M) man page. For procedures that use traceroute, refer to Displaying Routing Information With the traceroute Command.