This documentation has been moved
Implementing First Hop Security in IPv6
Downloads: This chapterpdf (PDF - 614.0KB) The complete bookPDF (PDF - 7.45MB) | Feedback

Implementing First Hop Security in IPv6

Table Of Contents

Implementing First Hop Security in IPv6

Finding Feature Information

Contents

Prerequisites for Implementing First Hop Security in IPv6

Restrictions for Implementing First Hop Security in IPv6

Information About Implementing First Hop Security in IPv6

IPv6 First-Hop Security Binding Table

IPv6 Device Tracking

IPv6 Port-Based Access List Support

IPv6 Global Policies

IPv6 RA Guard

IPv6 ND Inspection

Secure Neighbor Discovery in IPv6

IPv6 Neighbor Discovery Trust Models and Threats

SeND Protocol

SeND Deployment Models

Single CA Model

How to Implement First Hop Security in IPv6

Configuring the IPv6 Binding Table Content

Configuring IPv6 Device Tracking

Configuring IPv6 ND Inspection

Configuring IPv6 ND Inspection Globally

Applying IPv6 ND Inspection on a Specified Interface

Verifying and Troubleshooting IPv6 ND Inspection

Configuring IPv6 RA Guard

Applying IPv6 RA Guard on a Specified Interface

Verifying and Troubleshooting IPv6 RA Guard

Configuring SeND for IPv6

Configuring Certificate Servers to Enable SeND

Configuring a Host to Enable SeND

Configuring a Router to Enable SeND

Implementing IPv6 SeND

Configuring SeND Parameters

Configuring IPv6 PACL

Creating an IPv6 Access List

Configuring PACL Mode and Applying IPv6 PACL on an Interface

Configuration Examples for Implementing First Hop Security in IPv6

Example: IPv6 ND Inspection and RA Guard Configuration

Example: RA Guard Configuration

Example: Configuring PACL Mode and Applying IPv6 PACL on an Interface

Example: SeND Configuration Examples

Example: Configuring Certificate Servers

Example: Configuring a Host to Enable SeND

Example: Configuring a Router to Enable SeND

Example: Configuring a SeND Trustpoint in Router Mode

Example: Configuring SeND Trust Anchors in the Host Mode

Example: Configuring CGA Address Generation on an Interface

Additional References

Related Documents

Standards

MIBs

RFCs

Technical Assistance

Feature Information for Implementing First Hop Security in IPv6

Glossary


Implementing First Hop Security in IPv6


First Published: February 27, 2009
Last Updated: July 20, 2011

This document provides information about configuring features that comprise first hop security functionality in IPv6.

A database table of IPv6 neighbors connected to the switch is created from information sources such as Neighbor Discovery (ND) protocol snooping. This database, or binding, table is used by various IPv6 guard features (such as IPv6 ND Inspection, per-port address limit, IPv6 device tracking) to validate the link-layer address (LLA), the IPv4 or IPv6 address, and prefix binding of the neighbors to prevent spoofing and redirect attacks.

IPv6 ND Inspection learns and secures bindings for stateless autoconfiguration addresses in layer 2 neighbor tables. IPv6 ND inspection analyzes neighbor discovery messages in order to build a trusted binding table database, and IPv6 neighbor discovery messages that do not conform are dropped.

Router advertisements (RAs) are used by routers to announce themselves on the link. IPv6 RA Guard analyzes these RAs and can filter out bogus ones sent by unauthorized routers.

The per-port address limit feature enables an operator to specify a maximum number of IPv6 addresses allowed on a port of the switch. This function is achieved by filtering out ND messages sourced with addresses beyond the per-port address limit.

IPv6 Device Tracking provides IPv6 host liveness tracking so that a neighbor table can be immediately updated when an IPv6 host disappears.

The Secure Neighbor Discovery for Cisco IOS Software feature is designed to counter the threats of the ND protocol. Secure neighbor discovery (SeND) defines a set of neighbor discovery options and two neighbor discovery messages. SeND also defines a new autoconfiguration mechanism to establish address ownership. The IPv6 PACL feature adds IPv6 port-based ACL support.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest feature information and caveats, see 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 for Implementing First Hop Security in IPv6" section.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.

Contents

Prerequisites for Implementing First Hop Security in IPv6

Restrictions for Implementing First Hop Security in IPv6

Information About Implementing First Hop Security in IPv6

How to Implement First Hop Security in IPv6

Configuration Examples for Implementing First Hop Security in IPv6

Additional References

Feature Information for Implementing First Hop Security in IPv6

Glossary

Prerequisites for Implementing First Hop Security in IPv6

You should be familiar with the IPv6 neighbor discovery feature. For information about IPv6 neighbor discovery, see Implementing IPv6 Addressing and Basic Connectivity.

The SeND feature is available on crypto images because it involves using cryptographic libraries.

In order to use IPv6 port-based access list (PACL), you must know how to configure IPv6 access lists. For information about configuring IPv6 access lists, see Implementing Traffic Filters and Firewalls for IPv6 Security.

Restrictions for Implementing First Hop Security in IPv6

The IPv6 PACL feature is supported only in the ingress direction; it is not supported in the egress direction.

RA Guard in Cisco IOS Release 12.2(33)SXI4

The RA guard feature does not offer protection in environments where IPv6 traffic is tunneled.

This feature is supported only in hardware by programming the TCAM.

This feature can be configured only on a switchport interface in the ingress direction.

This feature supports only host mode.

This feature is supported only in the ingress direction; it is not supported in the egress direction.

This feature is supported on ether channel, but not on ether channel port members.

This feature is not supported on trunk ports with merge mode.

This feature is supported on auxiliary VLANs and PVLANs. In case of PVLANs, primary VLAN features are inherited and merged with port features.

Packets dropped by the RA guard feature can be spanned.

If the platform ipv6 acl icmp optimize neighbor-discovery command is configured, RA guard feature configuration should not be allowed and an error message should be displayed. This command adds default global ICMP entries that will override the RA guard ICMP entries.

Information About Implementing First Hop Security in IPv6

IPv6 First-Hop Security Binding Table

IPv6 Device Tracking

IPv6 Port-Based Access List Support

IPv6 Global Policies

Secure Neighbor Discovery in IPv6

IPv6 First-Hop Security Binding Table

A database table of IPv6 neighbors connected to the switch is created from information sources such as Neighbor Discovery (ND) protocol 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 prefix binding of the neighbors to prevent spoofing and redirect attacks.

IPv6 Device Tracking

The IPv6 device tracking feature provides IPv6 host liveness tracking so that a neighbor table can be immediately updated when an IPv6 host disappears. The feature tracks of the liveness of the neighbors connected through the Layer 2 switch on regular basis in order to revoke network access privileges as they become inactive.

IPv6 Port-Based Access List Support

The IPv6 PACL feature provides the ability to provide access control (permit or deny) on L2 switch ports for IPv6 traffic. IPv6 PACLs are similar to IPv4 PACLs, which provide access control on L2 switch ports for IPV4 traffic. They are supported only in ingress direction and in hardware.

PACL can filter ingress traffic on L2 interfaces based on L3 and L4 header information or non-IP L2 information.

IPv6 Global Policies

IPv6 global policies provide policy database services to features with regard to storing and accessing those policies. IPv6 ND inspection and IPv6 RA guard are IPv6 global policies features. Every time an ND inspection or RA guard is configured globally, the attributes of the policy are stored in the software policy database. The policy is then applied to an interface, and the software policy database entry is updated to include this interface to which the policy is applied.

IPv6 RA Guard

IPv6 ND Inspection

IPv6 RA Guard

IPv6 RA guard provides support for allowing the network administrator to block or reject unwanted or rogue RA guard messages that arrive at the network switch platform. RAs are used by routers to announce themselves on the link. The RA Guard feature analyzes these RAs and filters out bogus RAs sent by unauthorized routers. In host mode, all router advertisement and router redirect messages are disallowed on the port. The RA guard feature compares configuration information on the L2 device with the information found in the received RA frame. Once the L2 device has validated the content of the RA frame and router redirect frame against the configuration, it forwards the RA to its unicast or multicast destination. If the RA frame content is not validated, the RA is dropped.

IPv6 ND Inspection

IPv6 ND inspection learns and secures bindings for stateless autoconfiguration addresses in layer 2 neighbor tables. IPv6 ND inspection analyzes neighbor discovery messages in order to build a trusted binding table database, and IPv6 neighbor discovery messages that do not conform are dropped. SA neighbor discovery message is considered trustworthy if its IPv6-to-Media Access Control (MAC) mapping is verifiable.

This feature mitigates some of the inherent vulnerabilities for the neighbor discovery mechanism, such as attacks on duplicate address detection (DAD), address resolution, router discovery, and the neighbor cache.

Secure Neighbor Discovery in IPv6

IPv6 Neighbor Discovery Trust Models and Threats

SeND Protocol

SeND Deployment Models

IPv6 Neighbor Discovery Trust Models and Threats

There are three IPv6 neighbor discovery trust models, which are described as follows:

All authenticated nodes trust each other to behave correctly at the IP layer and not to send any neighbor discovery or router discovery (RD) messages that contain false information. This model represents a situation where the nodes are under a single administration and form a closed or semiclosed group. A corporate intranet is an example of this model.

A router trusted by the other nodes in the network to be a legitimate router that routes packets between the local network and any connected external networks. This router is trusted to behave correctly at the IP layer and not to send any neighbor discovery or RD messages that contain false information. This model represents a public network run by an operator. The clients pay the operator, have the operator's credentials, and trust the operator to provide the IP forwarding service. The clients do not trust each other to behave correctly; any other client node must be considered able to send falsified neighbor discovery and RD messages.

A model where the nodes do not directly trust each other at the IP layer. This model is considered suitable where a trusted network operator is not available.

Nodes on the same link use ND to discover each other's presence and link-layer addresses, to find routers, and to maintain reachability information about the paths to active neighbors. ND is used by both hosts and routers. The original ND specifications used IPsec to protect ND messages. However, not many detailed instructions for using IPsec are available. The number of manually configured security associations needed for protecting ND can be very large, which makes that approach impractical for most purposes. These threats need to be considered and eliminated.

SeND Protocol

The SeND protocol counters ND threats. It defines a set of new ND options, and two new ND messages (Certification Path Solicitation [CPS] and Certification Path Answer [CPA]). It also defines a new autoconfiguration mechanism to be used in conjunction with the new ND options to establish address ownership.

SeND defines the mechanisms defined in the following sections for securing ND:

Cryptographically Generated Addresses in SeND

Authorization Delegation Discovery

Cryptographically Generated Addresses in SeND

Cryptographically generated addresses (CGAs) are IPv6 addresses generated from the cryptographic hash of a public key and auxiliary parameters. This provides a method for securely associating a cryptographic public key with an IPv6 address in the SeND protocol.

The node generating a CGA address must first obtain a Rivest, Shamir, and Adelman (RSA) key pair (SeND uses an RSA public/private key pair). The node then computes the interface identifier part (which is the rightmost 64 bits) and appends the result to the prefix to form the CGA address.

CGA address generation is a one-time event. A valid CGA cannot be spoofed and the CGA parameters received associated to it is reused because the message must be signed with the private key that matches the public key used for CGA generation, which only the address owner will have.

A user cannot replay the complete SeND message (including the CGA address, CGA parameters, and CGA signature) because the signature has only a limited lifetime.

Authorization Delegation Discovery

Authorization delegation discovery is used to certify the authority of routers by using a trust anchor. A trust anchor is a third party that the host trusts and to which the router has a certification path. At a basic level, the router is certified by the trust anchor. In a more complex environment, the router is certified by a user that is certified by the trust anchor. In addition to certifying the router identity (or the right for a node to act as a router), the certification path contains information about prefixes that a router is allowed to advertise in router advertisements. Authorization delegation discovery enables a node to adopt a router as its default router.

SeND Deployment Models

Host-to-Host Deployment Without a Trust Anchor

Neighbor Solicitation Flow

Host-Router Deployment Model

Router Advertisement and Certificate Path Flows

Single CA Model

Host-to-Host Deployment Without a Trust Anchor

Deployment for SeND between hosts is straightforward. The hosts can generate a pair of RSA keys locally, autoconfigure their CGA addresses, and use them to validate their sender authority, rather than using a trust anchor to establish sender authority. Figure 1 illustrates this model.

Figure 1 Host-to-Host Deployment Model

Neighbor Solicitation Flow

In a neighbor solicitation scenario, hosts and routers in host mode exchange neighbor solicitations and neighbor advertisements. These neighbor solicitations and neighbor advertisements are secured with CGA addresses and CGA options, and have nonce, time stamp, and RSA neighbor discovery options. Figure 2 illustrates this scenario.

Figure 2 Neighbor Solicitation Flow

Host-Router Deployment Model

In many cases, hosts will not have access to the infrastructure that will enable them to obtain and announce their certificates. In these situations, hosts will secure their relationship using CGA, and secure their relationship with routers using a trusted anchor. When using RAs, SeND mandates that routers are authenticated through a trust anchor. Figure 3 illustrates this scenario.

Figure 3 Host-Router Deployment Model

Router Advertisement and Certificate Path Flows

Figure 4 shows the certificate exchange performed using certification path solicitation CPS/CPA SeND messages. In the illustration, Router R is certified (using an X.509 certificate) by its own CA (certificates CR). The CA itself (CA2) is certified by its own CA (certificates C2), and so on, up to a CA (CA0) that the hosts trusts. The certificate CR contains IP extensions per RFC 3779, which describes which prefix ranges the router R is allowed to announce (in RAs). This prefix range, certified by CA2, is a subset of CA2's own range, certified by CA1, and so on. Part of the validation process when a certification chain is received consists of validating the certification chain and the consistency of nested prefix ranges.

Figure 4 Router Advertisement and Certificate Path Flows

Single CA Model

The deployment model shown in Figure 3 can be simplified in an environment where both hosts and routers trust a single CA such as the Cisco certification server (CS). Figure 5 illustrates this model.

Figure 5 Single CA Deployment Model

How to Implement First Hop Security in IPv6

Configuring the IPv6 Binding Table Content

Configuring IPv6 Device Tracking

Configuring IPv6 ND Inspection

Configuring IPv6 RA Guard

Configuring SeND for IPv6

Configuring IPv6 PACL

Configuring the IPv6 Binding Table Content

SUMMARY STEPS

1. enable

2. configure terminal

3. ipv6 neighbor binding vlan vlan-id {interface type number | ipv6-address | mac-address} [tracking [disable | enable | retry-interval value] | reachable-lifetime value]

4. ipv6 neighbor binding max-entries entries [vlan-limit number | interface-limit number | mac-limit number]

5. ipv6 neighbor binding logging

6. exit

7. show ipv6 neighbor binding [vlan vlan-id | interface type number | ipv6 ipv6-address | mac mac-address]

DETAILED STEPS
 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

ipv6 neighbor binding vlan vlan-id {interface type number | ipv6-address | mac-address} [tracking [disable | enable | retry-interval value] | reachable-lifetime value]

Example:

Router(config)# ipv6 neighbor binding reachable-entries 100

Adds a static entry to the binding table database.

Step 4 

ipv6 neighbor binding max-entries entries [vlan-limit number | interface-limit number | mac-limit number]

Example:

Router(config)# ipv6 neighbor binding max-entries

Specifies the maximum number of entries that are allowed to be inserted in the binding table cache.

Step 5 

ipv6 neighbor binding logging

Example:
Router(config)# ipv6 neighbor binding logging

Enables the logging of binding table main events.

Step 6 

exit

Example:

Router(config)# exit

Exits global configuration mode, and places the router in privileged EXEC mode.

Step 7 

show ipv6 neighbor binding [vlan vlan-id | interface type number | ipv6 ipv6-address | mac mac-address]

Example:

Router# show ipv6 neighbor binding

Displays contents of a binding table.

Configuring IPv6 Device Tracking

Perform this task to provide fine grain control over the life cycle of an entry in the binding table for the IPv6 device tracking feature. This feature is available in Cisco IOS Release 12.2(50)SY. In order for IPv6 device tracking to work, the binding table needs to be populated (see the "Configuring the IPv6 Binding Table Content" section).

SUMMARY STEPS

1. enable

2. configure terminal

3. ipv6 neighbor tracking [retry-interval value]

DETAILED STEPS
 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

ipv6 neighbor tracking [retry-interval value]

Example:

Router(config)# ipv6 neighbor tracking

Tracks entries in the In order for this feat.

Configuring IPv6 ND Inspection

Configuring IPv6 ND Inspection Globally

Applying IPv6 ND Inspection on a Specified Interface

Verifying and Troubleshooting IPv6 ND Inspection

Configuring IPv6 ND Inspection Globally

SUMMARY STEPS

1. enable

2. configure terminal

3. ipv6 nd inspection policy policy-name

4. drop-unsecure

5. sec-level minimum value

6. device-role {host | monitor | router}

7. tracking {enable [reachable-lifetime {value | infinite}] | disable [stale-lifetime {value | infinite}]}

8. trusted-port

DETAILED STEPS
 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

ipv6 nd inspection policy policy-name

Example:

Router(config)# ipv6 nd inspection policy policy1

Defines the ND inspection policy name and enters the router into ND inspection policy configuration mode.

Step 4 

drop-unsecure

Example:

Router(config-nd-inspection)# drop-unsecure

Drops messages with no or invalid options or an invalid signature.

Step 5 

sec-level minimum value

Example:

Router(config-nd-inspection)# sec-level minimum 2

Specifies the minimum security level parameter value when CGA options are used.

Step 6 

device-role {host | monitor | router}

Example:

Router(config-nd-inspection)# device-role monitor

Specifies the role of the device attached to the port.

Step 7 

tracking {enable [reachable-lifetime {value | infinite}] | disable [stale-lifetime {value | infinite}]}

Example:

Router(config-nd-inspection)# tracking disable stale-lifetime infinite

Overrides the default tracking policy on a port.

Step 8 

trusted-port

Example:

Router(config-nd-inspection)# trusted-port

Configures a port to become a trusted port.

Applying IPv6 ND Inspection on a Specified Interface

SUMMARY STEPS

1. enable

2. configure terminal

3. interface type number

4. ipv6 nd inspection [attach-policy [policy policy-name] | vlan {add | except | none | remove | all} vlan [vlan1, vlan2, vlan3...]]]

DETAILED STEPS
 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface type number

Example:

Router(config)# interface fastethernet 0/0

Specifies an interface type and number, and places the router in interface configuration mode.

Step 4 

ipv6 nd inspection [attach-policy [policy policy-name] | vlan {add | except | none | remove | all} vlan [vlan1, vlan2, vlan3...]]]

Example:
Router(config-if)# ipv6 nd inspection 

Applies the ND inspection feature on the interface.

Verifying and Troubleshooting IPv6 ND Inspection

SUMMARY STEPS

1. enable

2. show ipv6 snooping capture-policy [interface type number]

3. show ipv6 snooping counters [interface type number]

4. show ipv6 snooping features

5. show ipv6 snooping policies [interface type number]

6. debug ipv6 snooping [binding-table | classifier | errors | feature-manager | filter acl | ha | hw-api | interface interface | memory | ndp-inspection | policy | vlan vlanid | switcher | filter acl | interface interface | vlanid]

DETAILED STEPS
 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

show ipv6 snooping capture-policy [interface type number]

Example:
Router# show ipv6 snooping capture-policy 
interface ethernet 0/0 

Displays snooping ND message capture policies.

Step 3 

show ipv6 snooping counter [interface type number]

Example:
Router# show ipv6 snooping counters interface 
Fa4/12 

Displays information about the packets counted by the interface counter.

Step 4 

show ipv6 snooping features

Example:
Router# show ipv6 snooping features 

Displays information about snooping features configured on the router.

Step 5 

show ipv6 snooping policies [interface type number]

Example:
Router# show ipv6 snooping policies

Displays information about the configured policies and the interfaces to which they are attached.

Step 6 

debug ipv6 snooping [binding-table | classifier | errors | feature-manager | filter acl | ha | hw-api | interface interface | memory | ndp-inspection | policy | vlan vlanid | switcher | filter acl | interface interface | vlanid]

Example:
Router# debug ipv6 snooping

Enables debugging for snooping information in IPv6.

Configuring IPv6 RA Guard

Applying IPv6 RA Guard on a Specified Interface

Verifying and Troubleshooting IPv6 RA Guard

Applying IPv6 RA Guard on a Specified Interface

SUMMARY STEPS

1. enable

2. configure terminal

3. interface type number

4. ipv6 nd raguard attach-policy [policy-name [vlan {add | except | none | remove | all} vlan [vlan1, vlan2, vlan3...]]]

DETAILED STEPS
 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface type number

Example:

Router(config)# interface Gigabit 0/0

Specifies an interface type and number, and places the router in interface configuration mode.

Step 4 

ipv6 nd raguard attach-policy [policy-name [vlan {add | except | none | remove | all} vlan [vlan1, vlan2, vlan3...]]]

Example:
Router(config-if)# ipv6 nd raguard 
attach-policy

Applies the RA guard feature on a specified interface.

Configuring IPv6 RA Guard in Cisco IOS Release 12.2(33)SXI4 and 12.2(54)SG

SUMMARY STEPS

1. enable

2. configure terminal

3. interface type number

4. ipv6 nd raguard

DETAILED STEPS
 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface type number

Example:

Router(config)# interface fastethernet 0/0

Specifies an interface type and number, and places the router in interface configuration mode.

Step 4 

ipv6 nd raguard

Example:

Router(config-if)# ipv6 nd raguard

Applies the IPv6 RA guard feature.

Verifying and Troubleshooting IPv6 RA Guard

SUMMARY STEPS

1. enable

2. show ipv6 nd raguard policy [policy-name]

3. debug ipv6 snooping raguard [filter | interface | vlanid]

DETAILED STEPS
 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

show ipv6 nd raguard policy [policy-name]

Example:
Router# show ipv6 nd raguard policy raguard1 

Displays RAs guard policy on all interfaces configured with RA guard.

Step 3 

debug ipv6 snooping raguard [filter | interface | vlanid]

Example:
Router# debug ipv6 snooping raguard

Enables debugging for snooping information in the IPv6 RA guard feature.

Configuring SeND for IPv6

Certificate servers are used to grant certificates after validating or certifying key pairs. A tool for granting certificates is mandatory in any SeND deployment. Many tools are available to grant certificates, for example, Open Secure Sockets Layer (OpenSSL) on Linux. However, very few certificate servers support granting certificates containing IP extensions. Cisco IOS certificate servers support every kind of certificate including the certificates containing the IP extensions.

SeND is available in host mode. The set of available functions on a host will be a subset of SeND functionality. CGA will be fully available and the prefix authorization delegation will be supported on the host side (sending CPS and receiving CPA).

To implement SeND, configure the host with the following parameters:

An RSA key pair used to generate CGA addresses on the interface.

A SeND modifier that is computed using the RSA key pair.

A key on the SeND interface.

CGAs on the SeND interface.

A Public Key Infrastructure (PKI) trustpoint, with minimum content; for example, the URL of the certificate server. A trust anchor certificate must be provisioned on the host.

SeND is also available in router mode. You can use the ipv6 unicast-routing command to configure a node to a router. To implement SeND, configure routers with the same elements as that of the host. The routers will need to retrieve certificates of their own from a certificate server. The RSA key and subject name of the trustpoint are used to retrieve certificates from a certificate server. Once the certificate has been obtained and uploaded, the router generates a certificate request to the certificate server and installs the certificate.

The following operations need to be completed before SeND is configured on the host or router:

Hosts are configured with one or more trust anchors.

Hosts are configured with an RSA key pair or configured with the capability to locally generate it. Note that for hosts not establishing their own authority via a trust anchor, these keys are not certified by any CA.

Routers are configured with RSA keys and corresponding certificate chains, or the capability to obtain these certificate chains that match the host trust anchor at some level of the chain.

While booting, hosts and routers must either retrieve or generate their CGAs. Typically, routers will autoconfigure their CGAs once and save them (along with the key pair used in the CGA operation) into their permanent storage. At a minimum, link-local addresses on a SeND interface should be CGAs. Additionally, global addresses can be CGAs.

Configuring Certificate Servers to Enable SeND

Configuring a Host to Enable SeND

Configuring a Router to Enable SeND

Configuring Certificate Servers to Enable SeND

Hosts and routers must be configured with RSA key pairs and corresponding certificate chains before the SeND parameters are configured. Perform the following task to configure the certificate server to grant certificates. Once the certificate server is configured, other parameters for the certificate server can be configured.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip http server

4. crypto pki trustpoint name

5. ip-extension [multicast | unicast] {inherit [ipv4 | ipv6] | prefix ipaddress | range min-ipaddress max-ipaddress}

6. revocation-check {[crl] [none] [ocsp]}

7. exit

8. crypto pki server name

9. grant auto

10. cdp-url url-name

11. no shutdown

DETAILED STEPS
 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

ip http server

Example:

Router(config)# ip http server

Configures the HTTP server.

Step 4 

crypto pki trustpoint name

Example:

Router(config)# crypto pki trustpoint CA

(Optional) Declares the trustpoint that your certificate server should use and enters ca-trustpoint configuration mode.

If you plan to use X.509 IP extensions, use this command. To automatically generate a CS trustpoint, go to Step 8.

Step 5 

ip-extension [multicast | unicast] {inherit [ipv4 | ipv6] | prefix ipaddress | range min-ipaddress max-ipaddress}

Example:

Router(ca-trustpoint)# ip-extension prefix 2001:100::/32

(Optional) Specifies that the IP extensions are included in a certificate request either for enrollment or generation of a certificate authority (CA) for the Cisco IOS CA.

Step 6 

revocation-check {[crl] [none] [ocsp]}

Example:

Router(ca-trustpoint)# revocation-check crl

(Optional) Sets one or more methods for revocation checking.

Step 7 

exit

Example:

Router(ca-trustpoint)# exit

Returns to global configuration mode.

Step 8 

crypto pki server name

Example:

Router(config)# crypto pki server CA

Configures the PKI server and places the router in server configuration mode.

Step 9 

grant auto

Example:

Router(config-server)# grant auto

(Optional) Grants all certificate requests automatically.

Step 10 

cdp-url url-name

Example:

Router(config-server)# cdp-url http://209.165.202.129/CA.crl

(Optional) Sets the URL name if the host is using a Certificate Revocation List (CRL).

Step 11 

no shutdown

Example:

Router(config-server)# no shutdown

Enables the certificate server.

Configuring a Host to Enable SeND

SeND is available in host mode. Before you can configure SeND parameters in host mode, first configure the host using the following commands. Once the host has been configured, SeND parameters can be configured on it.

Summary Steps

1. enable

2. configure terminal

3. crypto key generate rsa [general-keys | usage-keys | signature | encryption] [label key-label] [exportable] [modulus modulus-size] [storage devicename:] [on devicename:]

4. ipv6 cga modifier rsakeypair key-label sec-level {0 | 1}

5. crypto pki trustpoint name

6. enrollment [mode] [retry period minutes] [retry count number] url url [pem]

7. revocation-check {[crl] [none] [ocsp]}

8. exit

9. crypto pki authenticate name

10. ipv6 nd secured sec-level minimum value

11. interface type number

12. ipv6 cga rsakeypair key-label

13. ipv6 address ipv6-address/prefix-length link-local cga

14. ipv6 nd secured trustanchor trustanchor-name

15. ipv6 nd secured timestamp {delta value | fuzz value}

16. exit

17. ipv6 nd secured full-secure

DETAILED STEPS
 
Command or Action
Purpose

Step 1 

enable

Example:

Host> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Host# configure terminal

Enters global configuration mode.

Step 3 

crypto key generate rsa [general-keys | usage-keys | signature | encryption] [label key-label] [exportable] [modulus modulus-size] [storage devicename:] [on devicename:]

Example:

Host(config)# crypto key generate rsa label SEND modulus 1024

Configures the RSA key.

Step 4 

ipv6 cga modifier rsakeypair key-label sec-level {0 | 1}

Example:

Host(config)# ipv6 cga modifier rsakeypair SEND sec-level 1

Enables the RSA key to be used by SeND (generates the modifier).

Step 5 

crypto pki trustpoint name

Example:

Host(config)# crypto pki trustpoint SEND

Specifies the node trustpoint and enters ca-trustpoint configuration mode.

Step 6 

enrollment [mode] [retry period minutes] [retry count number] url url [pem]

Example:

Host(ca-trustpoint)# enrollment url http://209.165.200.254

Specifies the enrollment parameters of a CA.

Step 7 

revocation-check {[crl] [none] [ocsp]}

Example:

Host(ca-trustpoint)# revocation-check none

Sets one or more methods of revocation.

Step 8 

exit

Example:

Host(ca-trustpoint)# exit

Returns to global configuration mode.

Step 9 

crypto pki authenticate name

Example:

Host(config)# crypto pki authenticate SEND

Authenticates the certification authority (by getting the certificate of the CA).

Step 10 

ipv6 nd secured sec-level minimum value

Example:

Host(config)# ipv6 nd secured sec-level minimum 1

(Optional) Configures CGA.

You can provide additional parameters such as security level and key size.

In the example, the security level accepted by peers is configured.

Step 11 

interface type number

Example:

Host(config)# interface fastethernet 0/0

Specifies an interface type and number, and places the router in interface configuration mode.

Step 12 

ipv6 cga rsakeypair key-label

Example:

Host(config-if)# ipv6 cga rsakeypair SEND

(Optional) Configures CGA on interfaces.

Step 13 

ipv6 address ipv6-address/prefix-length link-local cga

Example:

Host(config-if)# ipv6 address FE80::260:3EFF:FE11:6770/23 link-local cga

Configures an IPv6 link-local address for the interface and enables IPv6 processing on the interface.

Step 14 

ipv6 nd secured trustanchor trustanchor-name

Example:

Host(config-if)# ipv6 nd secured trustanchor SEND

(Optional) Configures trusted anchors to be preferred for certificate validation.

Step 15 

ipv6 nd secured timestamp {delta value | fuzz value}

Example:

Host(config-if)# ipv6 nd secured timestamp delta 300

(Optional) Configures the timing parameters.

Step 16 

exit

Example:

Host(config-if)# exit

Returns to global configuration mode.

Step 17 

ipv6 nd secured full-secure

Example:

Host(config)# ipv6 nd secured full-secure

(Optional) Configures general SeND parameters.

In the example, secure mode is configured on SeND.

Configuring a Router to Enable SeND

SeND is available in the router mode. Perform this task before you can configure SeND parameters in router mode. Once the router has been configured, the SeND parameters can be configured on it.

Summary Steps

1. enable

2. configure terminal

3. crypto key generate rsa [general-keys | usage-keys | signature | encryption] [label key-label] [exportable] [modulus modulus-size] [storage devicename:] [on devicename:]

4. ipv6 cga modifier rsakeypair key-label sec-level {0 | 1}

5. crypto pki trustpoint name

6. subject-name [attr tag] [eq | ne | co | nc] string

7. rsakeypair key-label

8. revocation-check {[crl] [none] [ocsp]}

9. exit

10. crypto pki authenticate name

11. crypto pki enroll name

12. ipv6 nd secured sec-level [minimum value]

13. interface type number

14. ipv6 cga rsakeypair key-label

15. ipv6 address ipv6-address/prefix-length link-local cga

16. ipv6 nd secured trustanchor trustanchor-name

17. ipv6 nd secured timestamp {delta value | fuzz value}

18. exit

19. ipv6 nd secured full-secure

DETAILED STEPS
 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

crypto key generate rsa [general-keys | usage-keys | signature | encryption] [label key-label] [exportable] [modulus modulus-size] [storage devicename:] [on devicename:]

Example:

Router(config)# crypto key generate rsa label SEND modulus 1024

Configures the RSA key.

Step 4 

ipv6 cga modifier rsakeypair key-label sec-level {0 | 1}

Example:

Router(config)# ipv6 cga modifier rsakeypair SEND sec-level 1

Enables the RSA key to be used by SeND (generates the modifier).

Step 5 

crypto pki trustpoint name

Example:

Router(config)# crypto pki trustpoint SEND

Configures PKI for a single or multiple-tier CA, specifies the router trustpoint, and places the router in ca-trustpoint configuration mode.

Step 6 

subject-name [attr tag][eq | ne | co | nc] string

Example:

Router(ca-trustpoint)# subject-name C=FR, ST=PACA, L=Example, O=Cisco, OU=NSSTG, CN=router

Creates a rule entry.

Step 7 

rsakeypair key-label

Example:

Router(ca-trustpoint)# rsakeypair SEND

Binds the RSA key pair for SeND.

Step 8 

revocation-check {[crl] [none] [ocsp]}

Example:

Router(ca-trustpoint)# revocation-check none

Sets one or more methods of revocation.

Step 9 

exit

Example:

host(ca-trustpoint)# exit

Returns to global configuration mode.

Step 10 

crypto pki authenticate name

Example:

host(config)# crypto pki authenticate SEND

Authenticates the certification authority (by getting the certificate of the CA).

Step 11 

crypto pki enroll name

Example:

Router(config)# crypto pki enroll SEND

Obtains the certificates for the router from the CA.

Step 12 

ipv6 nd secured sec-level minimum value

Example:

Router(config)# ipv6 nd secured sec-level minimum 1

(Optional) Configures CGA and provides additional parameters such as security level and key size.

In the example, the minimum security level that SeND accepts from its peers is configured.

Step 13 

interface type number

Example:

Router(config)# interface fastethernet 0/0

Specifies an interface type and number, and places the router in interface configuration mode.

Step 14 

ipv6 cga rsakeypair key-label

Example:

Router(config-if)# ipv6 cga rsakeypair SEND

(Optional) Configures CGA on interfaces.

In the example, CGA is generated.

Step 15 

ipv6 address ipv6-address/prefix-length link-local cga

Example:

Router(config-if)# ipv6 address fe80::link-local cga

Configures an IPv6 link-local address for the interface and enables IPv6 processing on the interface.

Step 16 

ipv6 nd secured trustanchor trustpoint-name

Example:

Router(config-if)# ipv6 nd secured trustanchor SEND

(Optional) Configures trusted anchors to be preferred for certificate validation.

Step 17 

ipv6 nd secured timestamp {delta value | fuzz value}

Example:

Router(config-if)# ipv6 nd secured timestamp delta 300

(Optional) Configures the timing parameters.

Step 18 

exit

Example:

Router(config-if)# exit

Returns to global configuration mode.

Step 19 

ipv6 nd secured full-secure

Example:

Router(config)# ipv6 nd secured full-secure

(Optional) Configures general SeND parameters, such as secure mode and authorization method.

In the example, SeND security mode is enabled.

Implementing IPv6 SeND

Creating the RSA Key Pair and CGA Modifier for the Key Pair

Configuring Certificate Enrollment for a PKI

Configuring a Cryptographically Generated Address

Configuring SeND Parameters

Creating the RSA Key Pair and CGA Modifier for the Key Pair

SUMMARY STEPS

1. enable

2. configure terminal

3. crypto key generate rsa [general-keys | usage-keys | signature | encryption] [label key-label] [exportable] [modulus modulus-size] [storage devicename:] [on devicename:]

4. ipv6 cga modifier rsakeypair key-label sec-level {0 | 1}

DETAILED STEPS
 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

crypto key generate rsa [general-keys | usage-keys | signature | encryption] [label key-label] [exportable] [modulus modulus-size] [storage devicename:] [on devicename:]

Example:

Router(config)# crypto key generate rsa label SeND

Generates RSA key pairs.

Step 4 

ipv6 cga modifier rsakeypair key-label sec-level {0 | 1}

Example:

Router(config)# ipv6 cga modifier rsakeypair SeND sec-level 1

Generates the CGA modifier for a specified RSA key, which enables the key to be used by SeND.

Configuring Certificate Enrollment for a PKI

Certificate enrollment, which is the process of obtaining a certificate from a CA, occurs between the end host that requests the certificate and the CA. Each peer that participates in the PKI must enroll with a CA. In IPv6, you can autoenroll or manually enroll the device certificate.

SUMMARY STEPS

1. enable

2. configure terminal

3. crypto pki trustpoint name

4. subject-name [x.500-name]

5. enrollment [mode] [retry period minutes] [retry count number] url url [pem]

6. serial-number [none]

7. auto-enroll [percent] [regenerate]

8. password string

9. rsakeypair key-label [key-size [encryption-key-size]]

10. fingerprint ca-fingerprint

11. ip-extension [multicast | unicast] {inherit [ipv4 | ipv6] | prefix ipaddress | range min-ipaddress max-ipaddress}

12. exit

13. crypto pki authenticate name

14. exit

15. copy [/erase] [/verify | /noverify] source-url destination-url

16. show crypto pki certificates

17. show crypto pki trustpoints [status | label [status]]

DETAILED STEPS
 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

crypto pki trustpoint name

Example:

Router(config)# crypto pki trustpoint trustpoint1

Declares the trustpoint that your router should use and enters ca-trustpoint configuration mode.

Step 4 

subject-name [x.500-name]

Example:

Router(ca-trustpoint)# subject-name name1

Specifies the subject name in the certificate request.

Step 5 

enrollment [mode] [retry period minutes] [retry count number] url url [pem]

Example:

Router(ca-trustpoint)# enrollment url http://name1.example.com

Specifies the URL of the CA on which your router should send certificate requests.

Step 6 

serial-number [none]

Example:

Router(ca-trustpoint)# serial-number

(Optional) Specifies the router serial number in the certificate request.

Step 7 

auto-enroll [percent] [regenerate]

Example:

Router(ca-trustpoint)# auto-enroll

(Optional) Enables autoenrollment, allowing you to automatically request a router certificate from the CA.

Step 8 

password string

Example:

Router(ca-trustpoint)# password password1

(Optional) Specifies the revocation password for the certificate.

Step 9 

rsakeypair key-label [key-size [encryption-key-size]]

Example:

Router(ca-trustpoint)# rsakeypair SEND

Specifies which key pair to associate with the certificate.

Step 10 

fingerprint ca-fingerprint

Example:

Router(ca-trustpoint)# fingerprint 12EF53FA 355CD23E 12EF53FA 355CD23E

(Optional) Specifies a fingerprint that can be matched against the fingerprint of a CA certificate during authentication.

Step 11 

ip-extension [multicast | unicast] {inherit [ipv4 | ipv6] | prefix ipaddress | range min-ipaddress max-ipaddress}

Example:

Router(ca-trustpoint)# ip-extension unicast prefix 2001:100:1://48

Add IP extensions (IPv6 prefixes or range) to verify prefix list the router is allowed to advertise.

Step 12 

exit

Example:

Router(ca-trustpoint)# exit

Exits ca-trustpoint configuration mode and returns to global configuration mode.

Step 13 

crypto pki authenticate name

Example:

Router(config)# crypto pki authenticate name1

Retrieves and authenticates the CA certificate.

This command is optional if the CA certificate is already loaded into the configuration.

Step 14 

exit

Example:

Router(config)# exit

Exits global configuration mode and returns to privileged EXEC mode.

Step 15 

copy [/erase] [/verify | /noverify] source-url destination-url

Example:

Router# copy system:running-config nvram:startup-config

(Optional) Copies the running configuration to the NVRAM startup configuration.

Step 16 

show crypto pki certificates

Example:

Router# show crypto pki certificates

(Optional) Displays information about your certificates, the certificates of the CA, and RA certificates.

Step 17 

show crypto pki trustpoints [status | label [status]]

Example:

Router# show crypto pki trustpoints name1

(Optional) Displays the trustpoints configured in the router.

Configuring a Cryptographically Generated Address

Configuring General CGA Parameters

Configuring CGA Address Generation on an Interface

Configuring General CGA Parameters

SUMMARY STEPS

1. enable

2. configure terminal

3. ipv6 nd secured sec-level [minimum value]

4. ipv6 nd secured key-length [[minimum | maximum] value]

DETAILED STEPS
 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

ipv6 nd secured sec-level [minimum value]

Example:

Router(config)# ipv6 nd secured sec-level minimum 1

Configures the SeND security level.

Step 4 

ipv6 nd secured key-length [[minimum | maximum] value]

Example:

Router(config)# ipv6 nd secured key-length minimum 512

Configures SeND key-length options.

Configuring CGA Address Generation on an Interface

SUMMARY STEPS

1. enable

2. configure terminal

3. interface type number

4. ipv6 cga rsakeypair key-label

5. ipv6 address {ipv6-address/prefix-length [cga] | prefix-name sub-bits/prefix-length [cga]}

DETAILED STEPS
 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface type number

Example:

Router(config)# interface Ethernet 0/0

Specifies an interface type and number, and places the router in interface configuration mode.

Step 4 

ipv6 cga rsakeypair key-label

Example:

Router(config-if)# ipv6 cga rsakeypair SEND

Specifies which RSA key pair should be used on a specified interface.

Step 5 

ipv6 address {ipv6-address/prefix-length [cga] | prefix-name sub-bits/prefix-length [cga]}

Example:

Router(config-if)# ipv6 address 2001:0DB8:1:1::/64 cga

Configures an IPv6 address based on an IPv6 general prefix and enables IPv6 processing on an interface.

The cga keyword generates a CGA address.

Note The CGA link-local addresses must be configured by using the ipv6 address link-local command.

Configuring SeND Parameters

Configuring the SeND Trustpoint

Configuring SeND Trust Anchors on the Interface

Configuring Secured and Nonsecured Neighbor Discovery Message Coexistence Mode

Configuring SeND Parameters Globally

Configuring the SeND Time Stamp

Configuring the SeND Trustpoint

In router mode, the key pair used to generate the CGA addresses on an interface must be certified by the CA and the certificate sent on demand over the SeND protocol. One RSA key pair and associated certificate is enough for SeND to operate; however, users may use several keys, identified by different labels. SeND and CGA refer to a key directly by label or indirectly by trustpoint.

Multiple steps are required to bind SeND to a trustpoint. First, a key pair is generated. Then the device refers to it in a trustpoint, and next the SeND interface configuration points to the trustpoint. There are two reasons for the multiple steps:

The same key pair can be used on several SeND interfaces

The trustpoint contains additional information, such as the certificate, required for SeND to perform authorization delegation

A CA certificate must be uploaded for the referred trustpoint. The referred trustpoint is in reality a trusted anchor.

Several trustpoints can be configured, pointing to the same RSA keys, on a given interface. This function is useful if different hosts have different trusted anchors (that is, CAs that they trust). The router can the provide each host with the certificate signed by the CA they trust.

SUMMARY STEPS

1. enable

2. configure terminal

3. crypto key generate rsa [general-keys | usage-keys | signature | encryption] [label key-label] [exportable] [modulus modulus-size] [storage devicename:] [on devicename:]

4. ipv6 cga modifier rsakeypair key-label sec-level {0 | 1}

5. crypto pki trustpoint name

6. subject-name [x.500-name]

7. rsakeypair key-label [key-size [encryption-key-size]]

8. enrollment terminal [pem]

9. ip-extension [multicast | unicast] {inherit [ipv4 | ipv6] | prefix ipaddress | range min-ipaddress max-ipaddress}

10. exit

11. crypto pki authenticate name

12. crypto pki enroll name

13. crypto pki import name certificate

14. interface type number

15. ipv6 nd secured trustpoint trustpoint-name

DETAILED STEPS
 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

crypto key generate rsa [general-keys | usage-keys | signature | encryption] [label key-label] [exportable] [modulus modulus-size] [storage devicename:] [on devicename:]

Example:

Router(config)# crypto key generate rsa label SEND

Generates RSA key pairs.

Step 4 

ipv6 cga modifier rsakeypair key-label sec-level {0 | 1}

Example:

Router(config)# ipv6 cga modifier rsakeypair SEND sec-level 1

Generates the CGA modifier for a specified RSA key, which enables the key to be used by SeND.

Step 5 

crypto pki trustpoint name

Example:

Router(config)# crypto pki trustpoint trustpoint1

Declares the trustpoint that your router should use and enters ca-trustpoint configuration mode.

Step 6 

subject-name [x.500-name]

Example:

Router(ca-trustpoint)# subject-name name1

Specifies the subject name in the certificate request.

Step 7 

rsakeypair key-label [key-size [encryption-key-size]]

Example:

Router(ca-trustpoint)# rsakeypair SEND

Specifies which key pair to associate with the certificate.

Step 8 

enrollment terminal [pem]

Example:

Router(ca-trustpoint)# enrollment terminal

Specifies manual cut-and-paste certificate enrollment.

Step 9 

ip-extension [multicast | unicast] {inherit [ipv4 | ipv6] | prefix ipaddress | range min-ipaddress max-ipaddress}

Example:

Router(ca-trustpoint)# ip-extension unicast prefix 2001:100:1://48

Adds IP extensions to the router certificate request.

Step 10 

exit

Example:

Router(ca-trustpoint)# exit

Exits ca-trustpoint configuration mode and returns to global configuration mode.

Step 11 

crypto pki authenticate name

Example:

Router(config)# crypto pki authenticate trustpoint1

Authenticates the certification authority (by getting the certificate of the CA).

Step 12 

crypto pki enroll name

Example:

Router(config)# crypto pki enroll trustpoint1

Obtains the certificates for your router from the CA.

Step 13 

crypto pki import name certificate

Example:

Router(config)# crypto pki import trustpoint1 certificate

Imports a certificate manually via TFTP or as a cut-and-paste at the terminal.

Step 14 

interface type number

Example:

Router(config)# interface Ethernet 0/0

Specifies an interface type and number, and places the router in interface configuration mode.

Step 15 

ipv6 nd secured trustpoint trustpoint-name

Example:

Router(config-if)# ipv6 nd secured trustpoint trustpoint1

Enables SeND on an interface and specifies which trustpoint should be used.

Configuring SeND Trust Anchors on the Interface

This task can be performed only in host mode. The host must be configured with one or more trust anchors. As soon as SeND is bound to a trustpoint on an interface (see "Configuring the SeND Trustpoint" section), this trustpoint is also a trust anchor.

A trust anchor configuration consists of the following items:

A public key signature algorithm and associated public key, which may include parameters

A name

An optional public key identifier

An optional list of address ranges for which the trust anchor is authorized

Because PKI has already been configured, the trust anchor configuration is accomplished by binding SeND to one or several PKI trustpoints. PKI is used to upload the corresponding certificates, which contain the required parameters (such as name and key).

Perform this optional task to configure a trusted anchor on the interface. It allows you to select trust anchors listed in the CPS when requesting for a certificate. If you opt not to configure trust anchors, all the PKI trustpoints configured on the host will be considered.

SUMMARY STEPS

1. enable

2. configure terminal

3. crypto pki trustpoint name

4. enrollment terminal [pem]

5. exit

6. crypto pki authenticate name

7. interface type number

8. ipv6 nd secured trustanchor trustanchor-name

DETAILED STEPS
 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

crypto pki trustpoint name

Example:

Router(config)# crypto pki trustpoint anchor1

Declares the trustpoint that your router should use and enters ca-trustpoint configuration mode.

Step 4 

enrollment terminal [pem]

Example:

Router(ca-trustpoint)# enrollment terminal

Specifies manual cut-and-paste certificate enrollment.

Step 5 

exit

Example:
Router(ca-trustpoint)# exit

Returns to global configuration.

Step 6 

crypto pki authenticate name

Example:

Router(config)# crypto pki authenticate anchor1

Authenticates the certification authority (by getting the certificate of the CA).

Step 7 

interface type number

Example:

Router(config)# interface Ethernet 0/0

Specifies an interface type and number, and places the router in interface configuration mode.

Step 8 

ipv6 nd secured trustanchor trustanchor-name

Example:

Router(config-if)# ipv6 nd secured trustanchor anchor1

Specifies a trusted anchor on an interface and binds SeND to a trustpoint.

Configuring Secured and Nonsecured Neighbor Discovery Message Coexistence Mode

During the transition to SeND secured interfaces, network operators may want to run a particular interface with a mixture of nodes accepting secured and unsecured neighbor discovery messages. Perform this task to configure the coexistence mode for secure and nonsecure ND messages on the same interface.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface type number

4. ipv6 nd secured trustpoint trustpoint-name

5. no ipv6 nd secured full-secure

DETAILED STEPS
 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface type number

Example:

Router(config)# interface Ethernet 0/0

Specifies an interface type and number, and places the router in interface configuration mode.

Step 4 

ipv6 nd secured trustpoint trustpoint-name

Example:

Router(config-if)# ipv6 nd secured trustpoint trustpoint1

Enables SeND on an interface and specifies which trustpoint should be used.

Step 5 

no ipv6 nd secured full-secure

Example:

Router(config-if)# no ipv6 nd secured full-secure

Provides the coexistence mode for secure and nonsecure ND messages on the same interface.

Configuring SeND Parameters Globally

SUMMARY STEPS

1. enable

2. configure terminal

3. ipv6 nd secured key-length [[minimum | maximum] value]

4. ipv6 nd secured sec-level minimum value

DETAILED STEPS
 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

ipv6 nd secured key-length [[minimum | maximum] value]

Example:

Router(config)# ipv6 nd secured key-length minimum 512

Configures the SeND key-length options.

Step 4 

ipv6 nd secured sec-level minimum value

Example:

Router(config)# ipv6 nd secured sec-level minimum 2

Configures the minimum security level value that can be accepted from peers.

Configuring the SeND Time Stamp

SUMMARY STEPS

1. enable

2. configure terminal

3. interface type number

4. ipv6 nd secured timestamp {delta value | fuzz value}

DETAILED STEPS
 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface type number

Example:

Router(config)# interface Ethernet 0/0

Specifies an interface type and number, and places the router in interface configuration mode.

Step 4 

ipv6 nd secured timestamp {delta value | fuzz value}

Example:

Router(config-if)# ipv6 nd secured timestamp delta 600

Configures the SeND time stamp.

Configuring IPv6 PACL

Creating an IPv6 Access List

Configuring PACL Mode and Applying IPv6 PACL on an Interface

Creating an IPv6 Access List

The first task in configuring IPv6 PACL is to create an IPv6 access list. This task is described in detail in Implementing Traffic Filters and Firewalls for IPv6 Security.

Configuring PACL Mode and Applying IPv6 PACL on an Interface

Once you have configured the IPv6 access list you want to use, you must configure the PACL mode on the specified IPv6 L2 interface.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface type number

4. access-group mode {prefer {port | vlan} | merge}

5. ipv6 traffic-filter access-list-name {in | out}

DETAILED STEPS
 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface type number

Example:

Router(config)# interface fastethernet 0/0

Specifies an interface type and number, and places the router in interface configuration mode.

Step 4 

access-group mode {prefer {port | vlan} | merge}

Example:

Router(config-if)# access-group mode prefer port

Sets the mode for the specified layer 2 interface.

The no form of this command sets the mode to the default value, which is merge.

The prefer vlan keyword combination is not supported in IPv6.

Step 5 

ipv6 traffic-filter access-list-name {in | out}

Example:

Router(config-if)# ipv6 traffic-filter list1 in

Filters incoming IPv6 traffic on an interface.


Note The out keyword and therefore filtering of outgoing traffic is not supported in IPv6 PACL configuration.


Configuration Examples for Implementing First Hop Security in IPv6

Example: IPv6 ND Inspection and RA Guard Configuration

Example: RA Guard Configuration

Example: Configuring PACL Mode and Applying IPv6 PACL on an Interface

Example: SeND Configuration Examples

Example: IPv6 ND Inspection and RA Guard Configuration

This example provides information about the Ethernet 0/0 interface, on which the ND inspection and RA Guard features are configured:

Router# show ipv6 snooping capture interface ethernet 0/0

Hardware policy registered on Et0/0 
Protocol     Protocol value   Message   Value     Action    Feature 
ICMP         58               RS        85        punt      RA Guard 
                                                  punt      ND Inspection 
ICMP         58               RA        86        drop      RA guard 
                                                  punt      ND Inspection 
ICMP         58               NS        87        punt      ND Inspection 
ICM          58               NA        88        punt      ND Inspection 
ICMP         58               REDIR     89        drop      RA Guard 
                                                  punt      ND Inspection 

Example: RA Guard Configuration

This section provides a configuration example for the RA guard feature:

Router(config)# interface fastethernet 3/13

Router(config-if)# ipv6 nd raguard

Router# show run interface fastethernet 3/13 

Building configuration... 

Current configuration : 129 bytes 
! 
interface FastEthernet3/13 
 switchport 
 switchport access vlan 222 
 switchport mode access 
 access-group mode prefer port 
 ipv6 nd raguard 
end 

Example: Configuring PACL Mode and Applying IPv6 PACL on an Interface

Once you have configured the IPv6 access list you want to use, you can configure the PACL mode on a specified IPv6 switchport. This section uses an access list named list1, provides an example of how to configure PACL mode, and applies IPv6 PACL to a GigabitEthernet interface.

Router(config)# interface gigabitethernet 3/24
Router(config-if)# access-group mode prefer port
Router(config-if)# ipv6 traffic-filter list1 in

Example: SeND Configuration Examples

Example: Configuring Certificate Servers

The following example shows how to configure certificate servers:

crypto pki server CA
 issuer-name C=FR, ST=fr, L=example, O=cisco, OU=nsstg, CN=CA0  lifetime ca-certificate 
700 !
crypto pki trustpoint CA
 ip-extension prefix 2001::/16
 revocation-check crl
 rsakeypair CA
no shutdown

Note If you need to configure certificate servers without IP extensions, do not use the ip-extension command.


To display the certificate servers with IP extensions, use the show crypto pki certificates verbose command:

Router# show crypto pki certificates verbose

CA Certificate
  Status: Available
  Version: 3
  Certificate Serial Number (hex): 01
  Certificate Usage: Signature
  Issuer:
    c=FR
    st=fr
    l=example
    o=cisco
    ou=nsstg
    cn=CA0
  Subject:
    c=FR
    st=fr
    l=example
    o=cisco
    ou=nsstg
    cn=CA0
  Validity Date:
    start date: 09:50:52 GMT Feb 5 2009
    end   date: 09:50:52 GMT Jan 6 2011
  Subject Key Info:
    Public Key Algorithm: rsaEncryption
    RSA Public Key: (1024 bit)
  Signature Algorithm: MD5 with RSA Encryption
  Fingerprint MD5: 87DB764F 29367A65 D05CEE3D C12E0AC3
  Fingerprint SHA1: 04A06602 86AA72E9 43F2DB33 4A7D40A2 E2ED3325
  X509v3 extensions:
    X509v3 Key Usage: 86000000
      Digital Signature
      Key Cert Sign
      CRL Signature
    X509v3 Subject Key ID: 75B477C6 B2CA7BBE C7866657 57C84A32 90CEFB5A
    X509v3 Basic Constraints:
        CA: TRUE
    X509v3 Authority Key ID: 75B477C6 B2CA7BBE C7866657 57C84A32 90CEFB5A
    Authority Info Access:
    X509v3 IP Extension:
        IPv6:
          2001::/16
  Associated Trustpoints: CA

Example: Configuring a Host to Enable SeND

The following example shows how to configure a host to enable SeND:

enable
configure terminal
 crypto key generate rsa label SEND modulus 1024
The name for the keys will be: SEND
% The key modulus size is 1024 bits
% Generating 1024 bit RSA keys, keys will be non-exportable...[OK]
 ipv6 cga modifier rsakeypair SEND sec-level 1
 crypto pki trustpoint SEND
  enrollment url http://209.165.200.254
  revocation-check none
  exit
 crypto pki authenticate SEND
Certificate has the following attributes:
	Fingerprint MD5: FC99580D 0A280EB4 2EB9E72B 941E9BDA
	Fingerprint SHA1: 22B10EF0 9A519177 145EA4F6 73667837 3A154C53
% Do you accept this certificate? [yes/no]: yes 
Trustpoint CA certificate accepted.
 ipv6 nd secured sec-level minimum 1
 interface fastethernet 0/0
  ipv6 cga rsakeypair SEND
  ipv6 address FE80::260:3EFF:FE11:6770 link-local cga
  ipv6 nd secured trustanchor SEND
  ipv6 nd secured timestamp delta 300
  exit
 ipv6 nd secured full-secure

To verify the configuration use the show running-config command:

host# show running-config

Building configuration...
[snip]
crypto pki trustpoint SEND
 enrollment url http://209.165.200.225
 revocation-check none
!
interface Ethernet1/0
 ip address 209.165.202.129 255.255.255.0
 duplex half
 ipv6 cga rsakeypair SEND
 ipv6 address 2001:100::/64 cga

Example: Configuring a Router to Enable SeND

The following example shows how to configure the router to enable SeND:

enable
configure terminal
 crypto key generate rsa label SEND modulus 1024
 ipv6 cga modifier rsakeypair SEND sec-level 1
 crypto pki trustpoint SEND
  subject-name C=FR, ST=PACA, L=Example, O=Cisco, OU=NSSTG, CN=router
  rsakeypair SEND
  revocation-check none
  exit
 crypto pki authenticate SEND
Certificate has the following attributes:
	Fingerprint MD5: FC99580D 0A280EB4 2EB9E72B 941E9BDA
	Fingerprint SHA1: 22B10EF0 9A519177 145EA4F6 73667837 3A154C53
% Do you accept this certificate? [yes/no]: yes 
Trustpoint CA certificate accepted.
 crypto pki enroll SEND
% Start certificate enrollment ..
% Create a challenge password. You will need to verbally provide this
   password to the CA Administrator in order to revoke your certificate.
   For security reasons your password will not be saved in the configuration.
   Please make a note of it.
Password:
Re-enter password:

% The subject name in the certificate will include: C=FR, ST=fr, L=example, O=cisco, 
OU=nsstg, CN=route r % The subject name in the certificate will include: Router % Include 
the router serial number in the subject name? [yes/no]: no % Include an IP address in the 
subject name? [no]:

Request certificate from CA? [yes/no]: yes % Certificate request sent to Certificate 
Authority % The 'show crypto pki certificate SEND verbose' commandwill show the 
fingerprint.

*Feb  5 09:40:37.171: CRYPTO_PKI:  Certificate Request Fingerprint MD5: 
A6892F9F 23561949 4CE96BB8 CBC85 E64
*Feb  5 09:40:37.175: CRYPTO_PKI:  Certificate Request Fingerprint SHA1: 
30832A66 E6EB37DF E578911D 383F 96A0 B30152E7
*Feb  5 09:40:39.843: %PKI-6-CERTRET: Certificate received from Certificate Authority
 interface fastethernet 0/0
  ipv6 nd secured sec-level minimum 1
  ipv6 cga rsakeypair SEND
  ipv6 address fe80::link-local cga
  ipv6 nd secured trustanchor SEND
  ipv6 nd secured timestamp delta 300
  exit
 ipv6 nd secured full-secure

To verify that the certificates are generated, use the show crypto pki certificates command:

Router# show crypto pki certificates

Certificate
  Status: Available
  Certificate Serial Number: 0x15
  Certificate Usage: General Purpose
  Issuer:
    cn=CA
  Subject:
    Name: Router
    hostname=Router
    c=FR
    st=fr
    l=example
    o=cisco
    ou=nsstg
    cn=router
  Validity Date:
    start date: 09:40:38 UTC Feb 5 2009
    end   date: 09:40:38 UTC Feb 5 2010
  Associated Trustpoints: SEND

CA Certificate
  Status: Available
  Certificate Serial Number: 0x1
  Certificate Usage: Signature
  Issuer:
    cn=CA
  Subject:
    cn=CA
  Validity Date:
    start date: 10:54:53 UTC Jun 20 2008
    end   date: 10:54:53 UTC Jun 20 2011
  Associated Trustpoints: SEND

To verify the configuration, use the show running-config command:

Router# show running-config

Building configuration...
[snip]
crypto pki trustpoint SEND
 enrollment url http://209.165.201.1
 subject-name C=FR, ST=fr, L=example, O=cisco, OU=nsstg, CN=router  revocation-check none  
rsakeypair SEND !
interface Ethernet1/0
 ip address 209.165.200.225 255.255.255.0
 duplex half
 ipv6 cga rsakeypair SEND
 ipv6 address FE80:: link-local cga
 ipv6 address 2001:100::/64 cga 

Example: Configuring a SeND Trustpoint in Router Mode

The following example shows how to configure a SeND trustpoint in router mode:

enable
 configure terminal
 crypto key generate rsa label SEND 
  Choose the size of the key modulus in the range of 360 to 2048 for your
 General Purpose Keys. Choosing a key modulus greater than 512 may take
  a few minutes.
How many bits in the modulus [512]: 778
% Generating 778 bit RSA keys, keys will be non-exportable...[OK]
 ipv6 cga modifier rsakeypair SEND sec-level 1
 crypto pki trustpoint trstpt1
  subject-name C=FR, ST=fr, L=example, O=cisco, OU=nsstg, CN=sa14-72b
  rsakeypair SEND
  enrollment terminal
  ip-extension unicast prefix 2001:100:1://48
  exit
 crypto pki authenticate trstpt1
 crypto pki enroll trstpt1
 crypto pki import trstpt1 certificate
 interface Ethernet 0/0
  ipv6 nd secured trustpoint trstpt1

Example: Configuring SeND Trust Anchors in the Host Mode

The following example shows how to configure SeND trust anchors on an interface in the host mode:

enable
configure terminal
! Configure the location of the CS we trust !
 crypto pki trustpoint B1
  enrollment terminal
  crypto pki authenticate anchor1
  exit
! Only Query a certificate signed by the CS at B2 on this interface !
 interface Ethernet0/0
  ip address 204.209.1.54 255.255.255.0
  ipv6 cga rsakeypair SEND
  ipv6 address 2001:100::/64 cga
  ipv6 nd secured trustanchor anchor1

Example: Configuring CGA Address Generation on an Interface

The following example shows how to configure CGA address generation on an interface:

enable
 configure terminal
 interface fastEthernet 0/0
  ipv6 cga rsakeypair SEND
  ipv6 address 2001:100::/64 cga
  exit

Additional References

Related Documents

Related Topic
Document Title

IPv6 Neighbor Discovery

Implementing IPv6 Addressing and Basic Connectivity

ICMP in IPv6

Implementing IPv6 Addressing and Basic Connectivity

IPv6—IPv6 stateless autoconfiguration

Implementing IPv6 Addressing and Basic Connectivity

IPv6 access lists

Implementing Traffic Filters and Firewalls for IPv6 Security

IPv6 DHCP

Implementing DHCP for IPv6

Configuring certificate enrollment for a PKI

"Configuring Certificate Enrollment for a PKI" module in the Cisco IOS Security Configuration Guide

IPv6 commands

Cisco IOS IPv6 Command Reference

All Cisco IOS commands

Cisco IOS Master Command List, All Releases


Standards

Standard
Title

No new or modified standards are supported, and support for existing standards has not been modified.


MIBs

MIB
MIBs Link

None

To locate and download MIBs for selected platforms, Cisco software releases, and feature sets, use Cisco MIB Locator found at the following URL:

http://www.cisco.com/go/mibs


RFCs

RFC
Title

RFC 3756

IPv6 Neighbor Discovery (ND) Trust Models and Threats

RFC 3779

X.509 Extensions for IP Addresses and AS Identifiers

RFC 3971

Secure Neighbor Discovery (SeND)

RFC 3972

Cryptographically Generated Addresses (CGA)

RFC 6105

IPv6 Router Advertisement Guard


Technical Assistance

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.

http://www.cisco.com/cisco/web/support/index.html


Feature Information for Implementing First Hop Security in IPv6

Table 1 lists the features in this module and provides links to specific configuration information.

Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.


Note Table 1 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.


Table 1 Feature Information for Implementing First Hop Security in IPv6 

Feature Name
Releases
Feature Information

IPv6 Device Tracking

12.2(50)SY

This feature allows IPv6 host liveness to be tracked so the neighbor binding table can be immediately updated when an IPv6 host disappears.

The following sections provide information about this feature:

IPv6 Device Tracking

Configuring IPv6 PACL

Configuring IPv6 PACL

The following commands were introduced or modified: ipv6 neighbor binding, ipv6 neighbor binding down-lifetime, ipv6 neighbor binding logging, ipv6 neighbor binding max-entries, ipv6 neighbor binding stale-lifetime, ipv6 neighbor binding vlan, ipv6 neighbor tracking, show ipv6 neighbor binding.

IPv6 ND Inspection

12.2(50)SY

The IPv6 ND Inspection feature learns and secures bindings for stateless autoconfiguration addresses in layer 2 neighbor tables.

The following sections provide information about this feature:

IPv6 ND Inspection

Applying IPv6 ND Inspection on a Specified Interface

Example: IPv6 ND Inspection and RA Guard Configuration

The following commands were introduced: clear ipv6 snooping counters, debug ipv6 snooping, device-role, drop-unsecure, ipv6 nd inspection, ipv6 nd inspection policy, sec-level minimum, show ipv6 snooping capture-policy, show ipv6 snooping counters, show ipv6 snooping features, show ipv6 snooping policies, tracking, trusted-port.

IPv6 PACL

12.2(54)SG
12.2(33)SXI4
12.2(50)SY

The IPv6 PACL permits or denies the movement of traffic between Layer 3 (L3) subnets and VLANs, or within a VLAN.

The following sections provide information about this feature:

IPv6 Port-Based Access List Support

Configuring IPv6 PACL

Additional References

The following commands were introduced or modified: access-group mode, ipv6 traffic-filter.

IPv6 RA Guard

12.2(54)SG
12.2(33)SXI4
12.2(50)SY

IPv6 RA guard provides support for allowing the network administrator to block or reject unwanted or rogue RA guard messages that arrive at the network switch platform.

The following sections provide information about this feature:

IPv6 RA Guard

Configuring IPv6 RA Guard in Cisco IOS Release 12.2(33)SXI4 and 12.2(54)SG

Configuring IPv6 RA Guard in Cisco IOS Release 12.2(33)SXI4 and 12.2(54)SG

Verifying and Troubleshooting IPv6 RA Guard

Example: RA Guard Configuration

Secure Neighbor Discovery for Cisco IOS Software

12.4(24)T

The Secure Neighbor Discovery (SeND) protocol is designed to counter the threats of the ND protocol. SeND defines a set of neighbor discovery options and two neighbor discovery messages. SeND also defines a new autoconfiguration mechanism to establish address ownership.

The following sections provide information about this feature:

Secure Neighbor Discovery in IPv6

Configuring SeND Parameters

Example: SeND Configuration Examples

The following commands were introduced or modified: auto-enroll, crypto key generate rsa, crypto pki authenticate, crypto pki enroll, crypto pki import, enrollment terminal (ca-trustpoint), enrollment url (ca-trustpoint), fingerprint, ip-extension, ip http server, ipv6 address, ipv6 address link-local, ipv6 cga modifier rsakeypair, ipv6 cga modifier rsakeypair (interface), ipv6 nd secured certificate-db, ipv6 nd secured full-secure, ipv6 nd secured full-secure (interface), ipv6 nd secured key-length, ipv6 nd secured sec-level, ipv6 nd secured timestamp, ipv6 nd secured timestamp-db, ipv6 nd secured trustanchor, ipv6 nd secured trustpoint, password (ca-trustpoint), revocation-check, rsakeypair, serial-number (ca-trustpoint), show ipv6 cga address-db, show ipv6 cga modifier-db, show ipv6 nd secured certificates, show ipv6 nd secured counters interface, show ipv6 nd secured nonce-db, show ipv6 nd secured timestamp-db, subject-name.


Glossary

ACE —access control entry

ACL—access control list

CA—certification authority.

CGA—cryptographically generated address.

CPA—certificate path answer.

CPR—certificate path response.

CPS—certification path solicitation. The solicitation message used in the addressing process.

CRL—certificate revocation list.

CS—certification server.

CSR—certificate signing request.

DAD—duplicate address detection. A mechanism that ensures two IPv6 nodes on the same link are not using the same address.

DER—distinguished encoding rules. An encoding scheme for data values.

LLA—link-layer address.

MAC—media access control.

nonce—An unpredictable random or pseudorandom number generated by a node and used once. In SeND, nonces are used to assure that a particular advertisement is linked to the solicitation that triggered it.

non-SeND node—An IPv6 node that does not implement SeND but uses only the neighbor discovery protocol without security.

NUD—neighbor unreachability detection. A mechanism used for tracking neighbor reachability.

PACL—port-based access list.

PKI—public key infrastructure.

RA—router advertisement.

Router Authorization Certificate—A public key certificate.

RD—Router discovery allows the hosts to discover what routers exist on the link and what subnet prefixes are available. Router discovery is a part of the neighbor discovery protocol.

SeND node—An IPv6 node that implements SeND.

trust anchor—A trust anchor is an entity that the host trusts to authorize routers to act as routers. Hosts are configured with a set of trust anchors to protect router discovery.

ULA—unique local addressing.