Published On: August 6ᵗʰ, 2019 02:01

Security Configuration Guide: Zone-Based Policy Firewall, Cisco IOS XE Release 3S

This feature supports VRF-Aware Service Infrastructure (VASI) interfaces over IPv6 firewalls. This feature allows you to apply services such as access control lists (ACLs), Network Address Translation (NAT), policing, and zone-based firewalls to traffic that flows across two different virtual routing and forwarding (VRF) instances. VASI interfaces support the redundancy of Route Processors (RPs) and Forwarding Processors (FPs). VASI interfaces support IPv4 and IPv6 unicast traffic.

This module provides information about VASI interfaces and describes how to configure VASI interfaces.

Finding Feature Information

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.

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.

Restrictions for IPv6 Zone-Based Firewall Support over VASI Interfaces

  • Multiprotocol Label Switching (MPLS) traffic over VRF-Aware Software Infrastructure (VASI) interfaces is not supported.

  • IPv4 and IPv6 multicast traffic is not supported.

  • VASI interfaces do not support the attachment of queue-based features. The following commands are not supported on modular QoS CLI (MQC) policies that are attached to VASI interfaces:
    • bandwidth (policy-map class)
    • fair-queue
    • priority
    • queue-limit
    • random-detect
    • shape

Information About IPv6 Zone-Based Firewall Support over VASI Interfaces

VASI Overview

VRF-Aware Software Infrastructure (VASI) provides the ability to apply services such as, a firewall, IPsec, and Network Address Translation (NAT), to traffic that flows across different virtual routing and forwarding (VRF) instances. VASI is implemented by using virtual interface pairs, where each of the interfaces in the pair is associated with a different VRF instance. The VASI virtual interface is the next-hop interface for any packet that needs to be switched between these two VRF instances. VASI interfaces provide the framework to configure a firewall or NAT between VRF instances.

Each interface pair is associated with two different VRF instances. The pairing is done automatically based on the two interface indexes such that the vasileft interface is automatically paired to the vasiright interface. For example, in the figure below, vasileft1 and vasiright1 are automatically paired, and a packet entering vasileft1 is internally handed over to vasiright1.

On VASI interfaces, you can configure either static routing or dynamic routing with Internal Border Gateway Protocol (IBGP), Enhanced Interior Gateway Routing Protocol (EIGRP), or Open Shortest Path First (OSPF). IBGP dynamic-routing protocol restrictions and configurations are valid for IBGP routing configurations between VASI interfaces.

The following figure shows an inter-VRF VASI configuration on the same device.

Figure 1. Inter-VRF VASI Configuration

When an inter-VRF VASI is configured on the same device, the packet flow happens in the following order:
  1. A packet enters the physical interface that belongs to VRF 1 (Gigabit Ethernet 0/2/0.3).

  2. Before forwarding the packet, a forwarding lookup is done in the VRF 1 routing table. Vasileft1 is chosen as the next hop, and the Time to Live (TTL) value is decremented from the packet. Usually, the forwarding address is selected on the basis of the default route in the VRF. However, the forwarding address can also be a static route or a learned route. The packet is sent to the egress path of vasileft1 and then automatically sent to the vasiright1 ingress path.

  3. When the packet enters vasiright1, a forwarding lookup is done in the VRF 2 routing table, and the TTL is decremented again (second time for this packet).

  4. VRF 2 forwards the packet to the physical interface, Gigabit Ethernet 0/3/0.5.

The following figure shows how VASI works in a Multiprotocol Label Switching (MPLS) VPN configuration.


Note


In the following figure, MPLS is enabled on the Gigabit Ethernet interface, but MPLS traffic is not supported across VASI pairs.


Figure 2. VASI with an MPLS VPN Configuration

When VASI is configured with a Multiprotocol Label Switching (MPLS) VPN, the packet flow happens in the following order:
  1. A packet arrives on the MPLS interface with a VPN label.

  2. The VPN label is stripped from the packet, a forwarding lookup is done within VRF 2, and the packet is forwarded to vasiright1. The TTL value is decremented from the packet.

  3. The packet enters vasileft1 on the ingress path, and another forwarding lookup is done in VRF 1. The packet is sent to the egress physical interface in VRF1 (Gigabit Ethernet 0/2/0.3). The TTL is again decremented from the packet.

How to Configure IPv6 Zone-Based Firewall Support over VASI Interfaces

Configuring VRFs and Address Family Sessions

SUMMARY STEPS

1. enable

2. configure terminal

3. vrf definition vrf-name

4. address-family ipv6

5. exit-address-family

6. end


DETAILED STEPS
  Command or Action Purpose
Step 1 enable


Example:
Device> enable 
 
Enables privileged EXEC mode.
  • Enter your password if prompted.

 
Step 2 configure terminal


Example:
Device# configure terminal 
 

Enters global configuration mode.

 
Step 3 vrf definition vrf-name


Example:
Device(config)# vrf definition VRF1 
 

Configures a virtual routing and forwarding (VRF) routing table instance and enters VRF configuration mode.

 
Step 4 address-family ipv6


Example:
Device(config-vrf)# address-family ipv6 
 

Enters address family configuration mode and configures sessions that carry standard IPv6 address prefixes.

 
Step 5 exit-address-family


Example:
Device(config-vrf-af)# exit-address-family 
 

Exits address family configuration mode and enters VRF configuration mode.

 
Step 6 end


Example:
Device(config-vrf)# end 
 

Exits VRF configuration mode and enters privileged EXEC mode.

 

Configuring Class Maps and Policy Maps for VASI Support

SUMMARY STEPS

1. enable

2. configure terminal

3. ipv6 unicast-routing

4. class-map type inspect match-any class-map-name

5. match protocol name

6. match protocol name

7. exit

8. policy-map type inspect policy-map-name

9. class type inspect class-map-name

10. inspect

11. exit

12. class class-default

13. end


DETAILED STEPS
  Command or Action Purpose
Step 1 enable


Example:
Device> enable
 
Enables privileged EXEC mode.
  • Enter your password if prompted.

 
Step 2 configure terminal


Example:
Device# configure terminal
 

Enters global configuration mode.

 
Step 3 ipv6 unicast-routing


Example:
Device(config)# ipv6-unicast routing
 

Enables the forwarding of IPv6 unicast datagrams.

 
Step 4 class-map type inspect match-any class-map-name


Example:
Device(config)# class-map type inspect match-any c-map
 

Creates an inspect type class map and enters QoS class-map configuration mode.

 
Step 5 match protocol name


Example:
Device(config-cmap)# match protocol icmp
 

Configures a match criterion for a class map on the basis of a specified protocol.

 
Step 6 match protocol name


Example:
Device(config-cmap)# match protocol tcp
 

Configures a match criterion for a class map on the basis of a specified protocol.

 
Step 7 exit


Example:
Device(config-cmap)# exit
 

Exits QoS class-map configuration mode and enters global configuration mode.

 
Step 8 policy-map type inspect policy-map-name


Example:
Device(config)# policy-map type inspect p-map
 

Creates a protocol-specific inspect-type policy map and enters QoS policy-map configuration mode.

 
Step 9 class type inspect class-map-name


Example:
Device(config-pmap)# class type inspect c-map
 

Specifies the traffic class on which an action is to be performed and enters QoS policy-map class configuration mode.

 
Step 10 inspect


Example:
Device(config-pmap-c)# inspect
 

Enables stateful packet inspection.

 
Step 11 exit


Example:
Device(config-pmap-c)# exit
 

Exits QoS policy-map class configuration mode and enters QoS policy-map configuration mode.

 
Step 12 class class-default


Example:
Device(config-pmap)# class class-default
 
Applies the policy map settings to the predefined default class and enters QoS policy-map class configuration mode.
  • If traffic does not match any of the match criteria in the configured class maps, it is directed to the predefined default class.

 
Step 13 end


Example:
Device(config-pmap-c)# end
 

Exits QoS policy-map class configuration mode and enters privileged EXEC mode.

 

Configuring Zones and Zone Pairs for VASI Support

SUMMARY STEPS

1. enable

2. configure terminal

3. zone security zone-name

4. exit

5. zone-pair security zone-pair-name source source-zone destination destination-zone

6. service-policy type inspect policy-map-name

7. exit

8. interface type number

9. vrf forwarding vrf-name

10. no ip address

11. zone member security zone-name

12. ipv6 address ipv6-address/prefix-length

13. ipv6 enable

14. negotiation auto

15. exit

16. interface type number

17. no ip address

18. ipv6 address ipv6-address/prefix-length

19. ipv6 enable

20. negotiation auto

21. end


DETAILED STEPS
  Command or Action Purpose
Step 1 enable


Example:
Device> enable 
 
Enables privileged EXEC mode.
  • Enter your password if prompted.

 
Step 2 configure terminal


Example:
Device# configure terminal 
 

Enters global configuration mode.

 
Step 3 zone security zone-name


Example:
Device(config)# zone security in 
 
Creates a security zone and enters security zone configuration mode.
  • Your configuration must have two security zones to create a zone pair: a source and a destination zone.

  • In a zone pair, you can use the default zone as either the source or the destination zone.

 
Step 4 exit


Example:
Device(config-sec-zone)# exit 
 

Exits security zone configuration mode and enters global configuration mode.

 
Step 5 zone-pair security zone-pair-name source source-zone destination destination-zone


Example:
Device(config)# zone-pair security in-out source in destination out 
 
Creates a zone pair and enters security zone-pair configuration mode.
  • To apply a policy, you must configure a zone pair.

 
Step 6 service-policy type inspect policy-map-name


Example:
Device(config-sec-zone-pair)# service-policy type inspect p-map 
 
Attaches a policy map to a top-level policy map.
  • If a policy is not configured between a pair of zones, traffic is dropped by default.

 
Step 7 exit


Example:
Device(config-sec-zone-pair)# exit
 

Exits security zone-pair configuration mode and enters global configuration mode.

 
Step 8 interface type number


Example:
Device(config)# interface gigabitethernet 0/0/0 
 

Configures an interface and enters interface configuration mode.

 
Step 9 vrf forwarding vrf-name


Example:
Device(config-if)# vrf forwarding VRF1
 

Associates a virtual routing and forwarding (VRF) instance or a virtual network with an interface or subinterface.

 
Step 10 no ip address


Example:
Device(config-if)# no ip address
 

Removes an IP address or disables IP processing.

 
Step 11 zone member security zone-name


Example:
Device(config-if)# zone member security in
 

Attaches an interface to a security zone.

 
Step 12 ipv6 address ipv6-address/prefix-length


Example:
Device(config-if)# ipv6 address 2001:DB8:2:1234/64 
 

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

 
Step 13 ipv6 enable


Example:
Device(config-if)# ipv6 enable 
 

Enables IPv6 processing on an interface that has not been configured with an explicit IPv6 address.

 
Step 14 negotiation auto


Example:
Device(config-if)# negotiation auto 
 

Enables advertisement of speed, duplex mode, and flow control on a Gigabit Ethernet interface.

 
Step 15 exit


Example:
Device(config-if)# exit
 

Exits interface configuration mode and enters global configuration mode.

 
Step 16 interface type number


Example:
Device(config)# interface gigabitethernet 0/0/1 
 

Configures an interface and enters interface configuration mode.

 
Step 17 no ip address


Example:
Device(config-if)# no ip address
 

Removes an IP address or disables IP processing.

 
Step 18 ipv6 address ipv6-address/prefix-length


Example:
Device(config-if)# ipv6 address 2001:DB8:3:1234/64 
 

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

 
Step 19 ipv6 enable


Example:
Device(config-if)# ipv6 enable 
 

Enables IPv6 processing on an interface that has not been configured with an explicit IPv6 address.

 
Step 20 negotiation auto


Example:
Device(config-if)# negotiation auto 
 

Enables advertisement of speed, duplex mode, and flow control on a Gigabit Ethernet interface.

 
Step 21 end


Example:
Device(config-if)# end 
 

Exits interface configuration mode and enters privileged EXEC mode.

 

Configuring VASI Interfaces

SUMMARY STEPS

1. enable

2. configure terminal

3. interface type number

4. vrf forwarding vrf-name

5. ipv6 address ipv6-address/prefix-length link-local

6. ipv6 address ipv6-address/prefix-length

7. ipv6 enable

8. no keepalive

9. zone member security zone-name

10. exit

11. interface type number

12. ipv6 address ipv6-address/prefix-length link-local

13. ipv6 address ipv6-address/prefix-length

14. ipv6 enable

15. no keepalive

16. exit

17. ipv6 route ipv6-prefix/prefix-length interface-type interface-number ipv6-address

18. ipv6 route vrf vrf-name ipv6-prefix/prefix-length interface-type interface-number ipv6-address

19. end


DETAILED STEPS
  Command or Action Purpose
Step 1 enable


Example:
Device> enable
 
Enables privileged EXEC mode.
  • Enter your password if prompted.

 
Step 2 configure terminal


Example:
Device# configure terminal
 

Enters global configuration mode.

 
Step 3 interface type number


Example:
Device(config)# interface vasileft 1
 

Configures a VASI interface and enters interface configuration mode.

 
Step 4 vrf forwarding vrf-name


Example:
Device(config-if)# vrf forwarding VRF1
 

Associates a virtual routing and forwarding (VRF) instance or a virtual network with an interface or subinterface.

 
Step 5 ipv6 address ipv6-address/prefix-length link-local


Example:
Device(config-if)# ipv6 address FE80::8EB6:4FFF:FE6C:E701 link-local
 

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

 
Step 6 ipv6 address ipv6-address/prefix-length


Example:
Device(config-if)# ipv6 address 2001:DB8:4:1234/64
 

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

 
Step 7 ipv6 enable


Example:
Device(config-if)# ipv6 enable
 

Enables IPv6 processing on an interface that has not been configured with an explicit IPv6 address.

 
Step 8 no keepalive


Example:
Device(config-if)# no keepalive
 

Disables keepalive packets.

 
Step 9 zone member security zone-name


Example:
Device(config-if)# zone member security out
 

Attaches an interface to a security zone.

 
Step 10 exit


Example:
Device(config-if)# exit
 

Exits interface configuration mode and enters global configuration mode.

 
Step 11 interface type number


Example:
Device(config)# interface vasiright 1
 

Configures a VASI interface and enters interface configuration mode.

 
Step 12 ipv6 address ipv6-address/prefix-length link-local


Example:
Device(config-if)# ipv6 address FE80::260:3EFF:FE11:6770 link-local
 

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

 
Step 13 ipv6 address ipv6-address/prefix-length


Example:
Device(config-if)# ipv6 address 2001:DB8:4:1234/64
 

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

 
Step 14 ipv6 enable


Example:
Device(config-if)# ipv6 enable
 

Enables IPv6 processing on an interface that has not been configured with an explicit IPv6 address.

 
Step 15 no keepalive


Example:
Device(config-if)# no keepalive
 

Disables keepalive packets.

 
Step 16 exit


Example:
Device(config-if)# exit
 

Exits interface configuration mode and enters global configuration mode.

 
Step 17 ipv6 route ipv6-prefix/prefix-length interface-type interface-number ipv6-address


Example:
Device(config)# ipv6 route 2001::/64 vasileft 1 2001::/64
 

Establishes static IPv6 routes.

 
Step 18 ipv6 route vrf vrf-name ipv6-prefix/prefix-length interface-type interface-number ipv6-address


Example:
Device(config)# ipv6 route vrf vrf1 2001::/64 vasiright 1 2001::/64
 

Specifies all VRF tables or a specific VRF table for an IPv6 address.

 
Step 19 end


Example:
Device(config# end
 

Exits global configuration mode and enters privileged EXEC mode.

 

Configuration Examples for IPv6 Zone-Based Firewall Support over VASI Interfaces

Example: Configuring VRFs and Address Family Sessions

Device# configure terminal 
Device(config)# vrf definition VRF1 
Device(config-vrf)# address-family ipv6
Device(config-vrf-af)# exit-address-family
Device(config-vrf)# end 

Example: Configuring Class Maps and Policy Maps for VASI Support

Device# configure terminal
Device(config)# ipv6-unicast routing
Device(config)# class-map type inspect match-any c-map
Device(config-cmap)# match protocol icmp
Device(config-cmap)# match protocol tcp
Device(config-cmap)# match protocol udp
Device(config-cmap)# exit
Device(config)# policy-map type inspect p-map
Device(config-pmap)# class type inspect c-map
Device(config-pmap-c)# inspect
Device(config-pmap-c)# exit
Device(config-pmap)# class class-default
Device(config-pmap-c)# end

Example: Configuring Zones and Zone Pairs for VASI Support

Device# configure terminal
Device(config)# zone security in
Device(config)# exit
Device(config)# zone security out
Device(config)# exit
Device(config)# zone-pair security in-out source in destination out
Device(config-sec-zone-pair)# service-policy type inspect p-map
Device(config-sec-zone-pair)# exit 
Device(config)# interface gigabitethernet 0/0/0
Device(config-if)# vrf forwarding VRF1
Device(config-if)# no ip address
Device(config-if)# zone member security in
Device(config-if)# ipv6 address 2001:DB8:2:1234/64 
Device(config-if)# ipv6 enable
Device(config-if)# negotiation auto 
Device(config-if)# exit
Device(config)# interface gigabitethernet 0/0/1
Device(config-if)# no ip address
Device(config-if)# ipv6 address 2001:DB8:3:1234/64
Device(config-if)# ipv6 enable
Device(config-if)# negotiation auto 
Device(config-if)# end

Example: Configuring VASI Interfaces

Device# configure terminal
Device(config)# interface vasileft 1
Device(config-if)# vrf forwarding VRF1
Device(config-if)# ipv6 address FE80::8EB6:4FFF:FE6C:E701 link-local
Device(config-if)# ipv6 address 2001:DB8:4:1234/64
Device(config-if)# ipv6 enable
Device(config-if)# no keepalive
Device(config-if)# zone-member security out
Device(config-if)# exit
Device(config)# interface vasiright 1
Device(config-if)# ipv6 address FE80::260:3EFF:FE11:6770 link-local
Device(config-if)# ipv6 address 2001:DB8:4:1234/64
Device(config-if)# ipv6 enable
Device(config-if)# no keepalive
Device(config-if)# exit
Device(config)# ipv6 route 2001::/64 vasileft 1 2001::/64
Device(config)# ipv6 route vrf vrf1 2001::/64 vasiright 1 2001::/64
Device(config)# end      

Additional References for Firewall Stateful Interchassis Redundancy

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Feature Information for IPv6 Zone-Based Firewall Support over VASI Interfaces

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 Zone-Based Firewall Support VASI Interfaces

Feature Name

Releases

Feature Information

IPv6 Zone-Based Firewall Support over VASI Interfaces

Cisco IOS XE Release 3.7S

This feature supports VASI interfaces over IPv6 firewalls. This feature allows you to apply services such as access control lists (ACLs), Network Address Translation (NAT), policing, and zone-based firewalls to traffic that flows across two different virtual routing and forwarding (VRF) instances. VASI interfaces support the redundancy of Route Processors (RPs) and Forwarding Processors (FPs). VASI interfaces support IPv4 and IPv6 unicast traffic.

No commands were introduced or modified for this feature.