SAVI configuration in DHCPv6-only address assignment

As shown inFigure 133, Switch A is the DHCPv6 server. Switch B connects to the DHCPv6 server through interface GigabitEthernet 1/0/1, and connects to two DHCPv6 clients through interfaces GigabitEthernet 1/0/2 and GigabitEthernet 1/0/3. The three interfaces of Switch B belong to VLAN 2. The client can obtain IP address only through DHCPv6. Configure SAVI on Switch B to automatically bind the IP addresses assigned through DHCPv6 and permit only packets from bound addresses and link-local addresses.

Configure Switch B as follows:

• Enable SAVI.

• Enable DHCPv6 snooping. For more information about DHCPv6 snooping, see Layer 3—IP Services Configuration Guide.

• Enable link-local address ND snooping. For more information about ND snooping, see Layer 3—IP Services Configuration Guide.

• Enable ND detection in VLAN 2 to check the ND packets arrived on the ports. For more information about ND detection, see "Configuring ND attack defense."

• Configure a static IPv6 source guard binding entry on each interface connected to a client. This step is optional. If this step is not performed, SAVI does not check packets against static binding entries. For more information about static IPv6 source guard binding entries, see "Configuring IP source guard."

• Configure dynamic IPv6 source guard binding on the interfaces connected to the clients. For more information about dynamic IPv6 source guard binding, see "Configuring IP source guard."

Switch B checks the following packets:

• DHCPv6 protocol packets from DHCPv6 clients against link-local address ND snooping entries.

• ND protocol packets against link-local address ND snooping entries, DHCPv6 snooping entries, and static binding entries.

• IPv6 data packets from the clients against dynamic binding entries (including link-local address ND snooping entries and DHCPv6 snooping entries) applied on the interfaces connected to the clients and against static binding entries. The items to be examined include MAC address, IPv6 address, VLAN information, and ingress port.

# Enable SAVI.

<SwitchB> system-view
[SwitchB] ipv6 savi strict

# Enable IPv6.

[SwitchB] ipv6

# Globally enable DHCPv6 snooping.

[SwitchB] ipv6 dhcp snooping enable

# Assign interfaces GigabitEthernet 1/0/1, GigabitEthernet 1/0/2, and GigabitEthernet 1/0/3 to VLAN 2.

[SwitchB] vlan 2
[SwitchB-vlan2] port gigabitethernet 1/0/1 gigabitethernet 1/0/2 gigabitethernet 1/0/3

# Enable DHCPv6 snooping in VLAN 2.

[SwitchB-vlan2] ipv6 dhcp snooping vlan enable
[SwitchB] quit

# Configure interface GigabitEthernet 1/0/1 as a DHCP snooping trusted port.

[SwitchB] interface gigabitethernet 1/0/1
[SwitchB-GigabitEthernet1/0/1] ipv6 dhcp snooping trust
[SwitchB-GigabitEthernet1/0/1] quit

# Enable link-local address ND snooping and ND detection.

[SwitchB] ipv6 nd snooping enable link-local
[SwitchB] vlan 2
[SwitchB-vlan2] ipv6 nd snooping enable
[SwitchB-vlan2] ipv6 nd detection enable
[SwitchB-vlan2] quit

# Configure the dynamic IPv6 source guard binding function on downlink ports GigabitEthernet 1/0/2 and GigabitEthernet 1/0/3.

[SwitchB] interface gigabitethernet 1/0/2
[SwitchB-GigabitEthernet1/0/2] ipv6 verify source ipv6-address mac-address
[SwitchB-GigabitEthernet1/0/2] quit
[SwitchB] interface gigabitethernet 1/0/3
[SwitchB-GigabitEthernet1/0/3] ipv6 verify source ipv6-address mac-address
[SwitchB-GigabitEthernet1/0/3] quit