Contents

Configuring SAVI 1

About SAVI 1

SAVI application scenarios· 1

SAVI tasks at a glance· 1

Enabling SAVI 1

Configuring IPv6 source guard· 2

Configuring DHCPv6 snooping· 2

Configuring ND parameters· 2

Setting the entry deletion delay· 2

Enabling filtering entry logging· 3

SAVI configuration examples· 3

Example: Configuring DHCPv6-only SAVI 3

Example: Configuring SLAAC-only SAVI 4

Example: Configuring DHCPv6+SLAAC SAVI 6

 

Configuring SAVI

About SAVI

Source Address Validation Improvement (SAVI) checks the validity of the source addresses of global unicast IPv6 packets. It implements the validity check by using the ND snooping, DHCPv6 snooping, ND attack detection, and IP source guard features. SAVI checks only global unicast addresses and forwards the packets that pass the validity check. Packets sourced from an invalid address are dropped.

SAVI application scenarios

DHCPv6-only

The hosts connected to the SAVI-enabled device obtain addresses only through DHCPv6. DHCPv6 messages, ND messages (RA and RR messages excluded), and IPv6 data packets are checked based on DHCPv6 snooping entries and static IPv6 source guard binding entries.

SLAAC-only

The hosts connected to the SAVI-enabled device obtain addresses only through Stateless Address Autoconfiguration (SLAAC). In this scenario, SAVI drops all DHCPv6 messages. Only ND messages and IPv6 data packets are checked based on static IPv6 source guard binding entries.

DHCPv6+SLAAC

The hosts connected to the SAVI-enabled device obtain addresses through DHCPv6 and SLAAC. In this scenario, SAVI checks all DHCPv6 messages, ND messages, and IPv6 data packets based on DHCPv6 snooping entries and static IPv6 source guard binding entries.

SAVI tasks at a glance

To configure SAVI, perform the following tasks:

1.     Enabling SAVI

2.     Configuring IPv6 source guard

3.     Configuring DHCPv6 snooping

4.     Configuring ND parameters

5.     (Optional.) Setting the entry deletion delay

6.     (Optional.) Enabling filtering entry logging

Enabling SAVI

1.     Enter system view.

system-view

2.     Enable SAVI.

ipv6 savi strict

By default, SAVI is disabled.

Configuring IPv6 source guard

1.     Enable IPv6 source guard on an interface.

2.     (Optional.) Configure static IPv6SG bindings.

For more information about IPv6 source guard configuration, see "Configuring IP source guard."

Configuring DHCPv6 snooping

Restrictions and guidelines

Enable only DHCPv6 snooping for the SLAAC-only scenario.

Procedure

1.     Enable DHCPv6 snooping.

2.     Specify DHCPv6 snooping trusted ports.

3.     Enable recording client information in DHCPv6 snooping entries.

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

Configuring ND parameters

Restrictions and guidelines

Enable only ND attack detection for the DHCPv6-only scenario.

Procedure

1.     Enable ND snooping for global unicast addresses.

For more information about ND snooping, see IPv6 basics in Layer 3—IP Services Configuration Guide.

2.     Enable ND attack detection.

For more information about ND attack detection, see "Configuring ND attack defense."

3.     Specify ND trusted ports.

For more information about ND trusted ports, see "Configuring ND attack defense."

Setting the entry deletion delay

About this task

The entry deletion delay is the period of time that the device waits before deleting the DHCPv6 snooping entries and ND snooping entries for a down port.

Procedure

1.     Enter system view.

system-view

2.     Set the entry deletion delay.

ipv6 savi down-delay delay-time

By default, the entry deletion delay is 30 seconds.

Enabling filtering entry logging

About this task

Filtering entries are effective bindings used for filtering IPv6 packets by the source IPv6 address. Filtering entry logging enables the device to generate log messages for filtering entries. A log message contains the IPv6 address, MAC address, VLAN, and interface of a filtering entry.

The device sends filtering entry log messages to the information center. With the information center, you can set log message filtering and output rules, including output destinations. For more information about using the information center, see Network Management and Monitoring Configuration Guide.

Procedure

1.     Enter system view.

system-view

2.     Enable filtering entry logging.

ipv6 savi log enable filter-entry

By default, filtering entry logging is disabled.

SAVI configuration examples

Example: Configuring DHCPv6-only SAVI

Network configuration

As shown in Figure 1, configure SAVI on the switch to meet the following requirements:

·     Clients obtain IPv6 addresses only through DHCPv6.

·     SAVI checks the source addresses of DHCPv6 messages, ND messages (RA and RR messages excluded), and IPv6 data packets on FortyGigE 1/0/2 and FortyGigE 1/0/3.

Figure 1 Network diagram

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Procedure

# Enable SAVI.

<Switch> system-view

[Switch] ipv6 savi strict

# Assign FortyGigE 1/0/1 through FortyGigE 1/0/3 to VLAN 2.

[Switch] vlan 2

[Switch-vlan2] port fortygige 1/0/1 fortygige 1/0/2 fortygige 1/0/3

[Switch-vlan2] quit

# Enable DHCPv6 snooping.

[Switch] ipv6 dhcp snooping enable

# Configure FortyGigE 1/0/1 as a DHCPv6 snooping trusted port.

[Switch] interface fortygige 1/0/1

[Switch-FortyGigE1/0/1] ipv6 dhcp snooping trust

[Switch-FortyGigE1/0/1] quit

# Enable recording DHCPv6 snooping entries on FortyGigE 1/0/2 and FortyGigE 1/0/3.

[Switch] interface fortygige 1/0/2

[Switch-FortyGigE1/0/2] ipv6 dhcp snooping binding record

[Switch-FortyGigE1/0/2] quit

[Switch] interface fortygige 1/0/3

[Switch-FortyGigE1/0/3] ipv6 dhcp snooping binding record

[Switch-FortyGigE1/0/3] quit

# Enable ND attack detection.

[Switch] vlan 2

[Switch-vlan2] ipv6 nd detection enable

[Switch-vlan2] quit

# Enable IPv6 source guard on FortyGigE 1/0/2 and FortyGigE 1/0/3.

[Switch] interface fortygige 1/0/2

[Switch-FortyGigE1/0/2] ipv6 verify source ip-address mac-address

[Switch-FortyGigE1/0/2] quit

[Switch] interface fortygige 1/0/3

[Switch-FortyGigE1/0/3] ipv6 verify source ip-address mac-address

[Switch-FortyGigE1/0/3] quit

Example: Configuring SLAAC-only SAVI

Network configuration

As shown in Figure 2, configure SAVI on Switch B to meet the following requirements:

·     Hosts obtain IPv6 addresses only through SLAAC.

·     DHCPv6 messages are dropped on FortyGigE 1/0/1 through FortyGigE 1/0/3 in VLAN 2.

·     SAVI checks the source addresses of ND messages and IPv6 data packets on FortyGigE 1/0/1 and FortyGigE 1/0/2.

Figure 2 Network diagram

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Procedure

# Enable SAVI.

<SwitchB> system-view

[SwitchB] ipv6 savi strict

# Assign FortyGigE 1/0/1 through FortyGigE 1/0/3 to VLAN 2.

[SwitchB] vlan 2

[SwitchB-vlan2] port fortygige 1/0/1 fortygige 1/0/2 fortygige 1/0/3

[SwitchB-vlan2] quit

# Enable ND snooping for global unicast addresses in VLAN 2.

[SwitchB] vlan 2

[SwitchB-vlan2] ipv6 nd snooping enable global

# Enable ND attack detection for VLAN 2.

[SwitchB-vlan2] ipv6 nd detection enable

[SwitchB-vlan2] quit

# Enable DHCPv6 snooping.

[SwitchB] ipv6 dhcp snooping enable

# Configure FortyGigE 1/0/3 as an ND trusted port.

[SwitchB] interface fortygige 1/0/3

[SwitchB-FortyGigE1/0/3] ipv6 nd detection trust

[SwitchB-FortyGigE1/0/3] quit

# Enable IPv6 source guard on FortyGigE 1/0/1 and FortyGigE 1/0/2.

[SwitchB] interface fortygige 1/0/1

[SwitchB-FortyGigE1/0/1] ipv6 verify source ip-address mac-address

[SwitchB-FortyGigE1/0/1] quit

[SwitchB] interface fortygige 1/0/2

[SwitchB-FortyGigE1/0/2] ipv6 verify source ip-address mac-address

[SwitchB-FortyGigE1/0/2] quit

Example: Configuring DHCPv6+SLAAC SAVI

Network configuration

As shown in Figure 3, configure SAVI on Switch B to meet the following requirements:

·     Hosts obtain IP addresses through DHCPv6 or SLAAC.

·     SAVI checks the source addresses of DHCPv6 messages, ND messages, and IPv6 data packets on FortyGigE 1/0/3 through FortyGigE 1/0/5.

Figure 3 Network diagram

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Procedure

# Enable SAVI.

<SwitchB> system-view

[SwitchB] ipv6 savi strict

# Assign FortyGigE 1/0/1 through FortyGigE 1/0/5 to VLAN 2.

[SwitchB] vlan 2

[SwitchB-vlan2] port fortygige 1/0/1 fortygige 1/0/2 fortygige 1/0/3 fortygige 1/0/4 fortygige 1/0/5

# Enable DHCPv6 snooping.

[SwitchB] ipv6 dhcp snooping enable

# Enable recording DHCPv6 snooping entries on FortyGigE 1/0/3 through FortyGigE 1/0/5.

[SwitchB] interface fortygige 1/0/3

[SwitchB-FortyGigE1/0/3] ipv6 dhcp snooping binding record

[SwitchB-FortyGigE1/0/3] quit

[SwitchB] interface fortygige 1/0/4

[SwitchB-FortyGigE1/0/4] ipv6 dhcp snooping binding record

[SwitchB-FortyGigE1/0/4] quit

[SwitchB] interface fortygige 1/0/5

[SwitchB-FortyGigE1/0/5] ipv6 dhcp snooping binding record

[SwitchB-FortyGigE1/0/5] quit

# Configure FortyGigE 1/0/1 as a DHCPv6 snooping trusted port.

[SwitchB] interface fortygige 1/0/1

[SwitchB-FortyGigE1/0/1] ipv6 dhcp snooping trust

[SwitchB-FortyGigE1/0/1] quit

# Enable ND snooping for global unicast addresses in VLAN 2.

[SwitchB] vlan 2

[SwitchB-vlan2] ipv6 nd snooping enable global

# Enable ND attack detection for VLAN 2.

[SwitchB-vlan2] ipv6 nd detection enable

[SwitchB-vlan2] quit

# Configure FortyGigE 1/0/2 as an ND trusted port.

[SwitchB] interface fortygige 1/0/2

[SwitchB-FortyGigE1/0/2] ipv6 nd detection trust

[SwitchB-FortyGigE1/0/2] quit

# Enable IPv6 source guard on FortyGigE 1/0/3 through FortyGigE 1/0/5.

[SwitchB] interface fortygige 1/0/3

[SwitchB-FortyGigE1/0/3] ipv6 verify source ip-address mac-address

[SwitchB-FortyGigE1/0/3] quit

[SwitchB] interface fortygige 1/0/4

[SwitchB-FortyGigE1/0/4] ipv6 verify source ip-address mac-address

[SwitchB-FortyGigE1/0/4] quit

[SwitchB] interface fortygige 1/0/5

[SwitchB-FortyGigE1/0/5] ipv6 verify source ip-address mac-address