Contents
A database table of IPv6 neighbors connected to a device is created from information sources such as Neighbor Discovery Protocol (NDP) snooping. This database, or binding, table is used by various IPv6 guard features to prevent spoofing and redirect attacks.
The IPv6 first-hop security binding table recovery mechanism enables the binding table to recover in the event of a device reboot.
Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
You should be familiar with the IPv6 Neighbor Discovery feature. For information about IPv6 neighbor discovery, see the "Implementing IPv6 Addressing and Basic Connectivity" module.
You should be familiar with the IPv6 Destination Guard feature. For information, see the "IPv6 Destination Guard" module.
A database table of IPv6 neighbors connected to the device is created from information sources such as NDP snooping. This database, or binding table, is used by various IPv6 guard features to validate the link-layer address (LLA), the IPv4 or IPv6 address, and the prefix binding of the neighbors to prevent spoofing and redirect attacks.
The IPv6 first-hop security binding table recovery mechanism enables the binding table to recover in the event of a device reboot.
The recovery mechanism will block any data traffic sourced from an unknown source, that is a source not already specified in the binding table and previously learnt via NDP or Dynamic Host Configuration Protocol (DHCP) gleaning.
Note |
For more information on the IPv6 destination guard, see the "IPv6 Destination Guard" module. |
The IPv6 First-Hop Security Binding Table Recovery Mechanism feature introduces the capability to provide a prefix list that is matched before the recovery is attempted for both DHCP and NDP.
If an address does not match the prefix list associated with the protocol, then the recovery of the binding table entry will not be attempted with that protocol. The prefix list should correspond to the prefixes that are valid for address assignment in the Layer 2 domain using the protocol. The default is that there is no prefix list, in which case the recovery is attempted for all addresses. The command to associate a prefix list to a protocol is protocol {dhcp | ndp} [prefix-list prefix-list-name].
For more information on how to configure IPv6 prefix lists, see the "How to Implement RIP for IPv6" module.
Command or Action | Purpose | |
---|---|---|
Step 1
|
enable
Example: Device> enable |
Enables privileged EXEC mode. |
Step 2
|
configure terminal
Example: Device# configure terminal |
Enters global configuration mode. |
Step 3
|
ipv6 snooping policy snooping-policy-id
Example: Device(config)# ipv6 snooping policy 200 |
Enters IPv6 snooping configuration mode and allows you to modify the configuration of the snooping policy specified. |
Step 4
|
protocol {dhcp | ndp} [prefix-list prefix-list-name]
Example: Device(config-ipv6-snooping)# protocol dhcp prefix-list dhcp_prefix_list |
Associates a recovery protocol (DHCP or NDP) with a prefix list. |
Step 5
|
end
Example: Device(config-ipv6-snooping)# exit |
Exits IPv6 snooping configuration mode and returns to privileged EXEC mode. |
ipv6 dhcp-client leasequery server 2001:db8::1 vlan 100 ipv6 neighbor binding vlan 100 2001:db8::1 interface ethernet3/0 ipv6 prefix-list abc permit 2001:DB8::/64 ge 128 ipv6 snooping policy xyz destination-glean recovery dhcp protocol dhcp prefix-list abc ipv6 destination-guard policy xyz exit ipv6 dhcp guard policy server_side device-role server vlan configuration 100 ipv6 snooping attach-policy xyz ipv6 destination-guard attach-policy xyz interface ethernet3/0 switchport switchport access vlan 100 switchport mode access duplex auto ipv6 dhcp guard attach-policy server_side interface vlan100 no ip address ipv6 address 2001:DB8::100/64
The following example shows that NDP will be used for the recovery for all addresses and that DHCP will be used to recover addresses that match the prefix list called dhcp_prefix_list:
Device(config-ipv6-snooping)# protocol ndp Device(config-ipv6-snooping)# protocol dhcp prefix-list dhcp_prefix_list
Related Topic | Document Title |
---|---|
Cisco IOS commands |
|
IPv6 commands: complete command syntax, command mode, defaults, usage guidelines, and examples |
|
IPv6 neighbor discovery |
"Implementing IPv6 Addressing and Basic Connectivity" module |
IPv6 destination guard |
"IPv6 Destination Guard" module |
IPv6 prefix lists |
"How to Implement RIP for IPv6" module |
Description | Link |
---|---|
The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password. |
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Table 1 | Feature Information for IPv6 First-Hop Security Binding Table |
Feature Name | Releases | Feature Information |
---|---|---|
IPv6 First-Hop Security Binding Table |
15.2(4)S |
A database table of IPv6 neighbors connected to the device is created from information sources such as NDP snooping. This database, or binding, table is used by various IPv6 guard features to prevent spoofing and redirect attacks. |
IPv6 First-Hop Security Binding Table Recovery Mechanism |
15.2(4)S |
The IPv6 first-hop security binding table recovery mechanism enables the binding table to recover in the event of a device reboot. The following commands were introduced: destination-glean, protocol (IPv6). |