HPE 5920 series

224
Examples
# Enable sending ICMPv6 redirect messages.
<Sysname> system-view
[Sysname] ipv6 redirects enable
ipv6 temporary-address
Use ipv6 temporary-address to enable the system to generate a temporary IPv6 address.
Use undo ipv6 temporary-address to disable temporary IPv6 address generation and remove the
existing temporary addresses.
Syntax
ipv6 temporary-address [ valid-lifetime preferred-lifetime ]
undo ipv6 temporary-address
Default
The system does not generate any temporary IPv6 address.
Views
System view
Predefined user roles
network-admin
Parameters
valid-lifetime: Specifies the valid lifetime for temporary IPv6 addresses, in the range of 600 to
4294967295 seconds. The default valid lifetime is 604800 seconds (7 days). The valid lifetime must
be greater than or equal to the preferred lifetime.
preferred-lifetime: Specifies the preferred lifetime for temporary IPv6 addresses, in the range of 600
to 4294967295 seconds. The default preferred lifetime is 86400 seconds (1 day).
Usage guidelines
You must enable stateless autoconfiguration before configuring the temporary address function.
The stateless address autoconfiguration enables an interface to automatically generate an IPv6
global unicast address by using the address prefix in the received RA message and the interface ID.
On an IEEE 802 interface (such as an Ethernet interface or a VLAN interface), the interface ID is
generated based on the MAC address of the interface and is globally unique. An attacker can exploit
this rule to easily identify the sending device.
To fix the vulnerability, you can enable the temporary address function. With this function, an IEEE
802 interface generates the following addresses:
•
Public IPv6 address—Includes an address prefix in the RA message and a fixed interface ID
generated based on the MAC address of the interface.
•
Temporary IPv6 address—Includes an address prefix in the RA message and a random
interface ID generated through MD5.
When the valid lifetime of a temporary IPv6 address expires, the system removes the address and
generates a new one. This enables the system to send packets with different source addresses
through the same interface. The preferred lifetime and valid lifetime for a temporary IPv6 address are
determined as follows:
•
The preferred lifetime of a temporary IPv6 address takes the smaller of the following values:
 The preferred lifetime of the address prefix in the RA message.