R0106-HP MSR Router Series Layer 3 - IP Services Configuration Guide(V7)

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Ste
p
Command Remarks
3. Enable stateless address
autoconfiguration.
ipv6 address auto
By default, no IPv6 global unicast
address is configured on an interface.
Using the undo ipv6 address auto
command on an interface removes all
IPv6 global unicast addresses and
link-local addresses that are
automatically generated on the
interface.
After this configuration, the interface automatically generates 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 identify the sending device easily.
To fix the vulnerability, you can configure the temporary address function. With this function, an IEEE 802
interface generates the following addresses:
• Public IPv6 address—Includes the address prefix in the RA message and a fixed interface ID
generated based on the MAC address of the interface.
• Temporary IPv6 address—Includes the address prefix in the RA message and a random interface
ID generated through MD5.
You can also configure the interface to preferentially use the temporary IPv6 address as the source
address of sent packets. When the valid lifetime of the temporary IPv6 address expires, the interface
removes the address and generates a new one. This function enables the system to send packets with
different source addresses through the same interface. If the temporary IPv6 address cannot be used
because of a DAD conflict, the public IPv6 address is used.
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.
{ The preferred lifetime configured for temporary IPv6 addresses minus DESYNC_FACTOR (a
random number ranging from 0 to 600 seconds).
• The valid lifetime of a temporary IPv6 address takes the smaller of the following values:
{ The valid lifetime of the address prefix.
{ The valid lifetime configured for temporary IPv6 addresses.
To configure the temporary address function:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enable the system to generate a
temporary IPv6 address.
ipv6 temporary-address
[ valid-lifetime preferred-lifetime ]
By default, the system does not
generate any temporary IPv6
address.
3. Enable the system to
preferentially use the temporary
IPv6 address as the source
address of the packet.
ipv6 prefer temporary-address
By default, the system does not
preferentially use the temporary
IPv6 address as the source address
of the packet.