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Table Of Contents
Implementing Traffic Filters for IPv6 Security
Prerequisites for Implementing Traffic Filters for IPv6 Security
Restrictions for Implementing Traffic Filters for IPv6 Security
Information About Implementing Traffic Filters for IPv6 Security
Access Control Lists for IPv6 Traffic Filtering
Virtual Fragmentation Reassembly
Access Class Filtering in IPv6
SSO/ISSU Support for Per-User IPv6 ACL for PPP Sessions
How to Implement Traffic Filters for IPv6 Security
Configuring IPv6 Traffic Filtering
Creating and Configuring an IPv6 ACL for Traffic Filtering
Applying the IPv6 ACL to an Interface
Creating an IPv6 ACL to Provide Access Class Filtering
Applying an IPv6 ACL to the Virtual Terminal Line
Enabling IPv6 Template Processing
Troubleshooting IPv6 Security Configuration and Operation
Configuration Examples for Implementing Traffic Filters for IPv6 Security
Example: Configuring an Access List on the Router
Example: Route Processor Forwarding Manager ACL Configuration
Example: Forwarding Processor Forwarding Manager ACL Configuration
Example: Applying an IPv6 Access List to an Interface
Example: Route Processor Forwarding Manager ACL Application to an Interface
Example: Forwarding Processor Forwarding Manager ACL Application to an Interface
Example: IPv6 Template ACL Processing
Example: Displaying Access List Statistics
Feature Information for Implementing Traffic Filters for IPv6 Security
Implementing Traffic Filters for IPv6 Security
First Published: May 5, 2008Last Updated: February 14, 2011This module describes how to configure Cisco IOS XE IPv6 traffic filter and firewall features for your Cisco networking devices. These security features can protect your network from degradation or failure and also from data loss or compromised security resulting from intentional attacks and from unintended but damaging mistakes by well-meaning network users.
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 Traffic Filters for IPv6 Security" 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
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Prerequisites for Implementing Traffic Filters for IPv6 Security
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Prerequisites for Implementing Traffic Filters for IPv6 Security
You should be familiar with IPv6 addressing and basic configuration. Refer to the Implementing IPv6 Addressing and Basic Connectivity module for more information.
Restrictions for Implementing Traffic Filters for IPv6 Security
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Information About Implementing Traffic Filters for IPv6 Security
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Access Control Lists for IPv6 Traffic Filtering
The standard ACL functionality in IPv6 is similar to standard ACLs in IPv4. Access lists determine what traffic is blocked and what traffic is forwarded at router interfaces and allow filtering based on source and destination addresses, inbound and outbound to a specific interface. Each access list has an implicit deny statement at the end. IPv6 ACLs are defined and their deny and permit conditions are set using the ipv6 access-list command with the deny and permit keywords in global configuration mode.
Named and tagged ACLs are both supported in IPv6:
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IPv6 Packet Inspection
The following header fields are all used for IPv6 inspection—traffic class, flow label, payload length, next header, hop limit, and source or destination address. For further information on and descriptions of the IPv6 header fields, see RFC 2474.
Tunneling Support
IPv6 packets tunneled in IPv4 are not inspected. If a tunnel terminates on a router, and IPv6 traffic exiting the tunnel is nonterminating, then the traffic is inspected.
Virtual Fragmentation Reassembly
When virtual fragmentation reassembly (VFR) is enabled, VFR processing begins after ACL input lists are checked against incoming packets. The incoming packets are tagged with the appropriate VFR information.
Access Class Filtering in IPv6
Filtering incoming and outgoing connections to and from the router based on an IPv6 ACL is performed using the ipv6 access-class command in line configuration mode. The ipv6 access-class command is similar to the access-class command, except the IPv6 ACLs are defined by a name. If the IPv6 ACL is applied to inbound traffic, the source address in the ACL is matched against the incoming connection source address and the destination address in the ACL is matched against the local router address on the interface. If the IPv6 ACL is applied to outbound traffic, the source address in the ACL is matched against the local router address on the interface and the destination address in the ACL is matched against the outgoing connection source address. We recommend that identical restrictions are set on all the virtual terminal lines because a user can attempt to connect to any of them.
IPv6 Template ACL
When user profiles are configured using vendor-specific attribute (VSA) Cisco AV-pairs, similar per-user IPv6 ACLs may be replaced by a single template ACL. That is, one ACL represents many similar ACLs. By using IPv6 template ACLs, you can increase the total number of per-user ACLs while minimizing the memory and Ternary Content Addressable Memory (TCAM) resources needed to support the ACLs.
The IPv6 Template ACL feature can create templates using the following ACL fields:
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ACL names are dynamically generated by this feature; for example:
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SSO/ISSU Support for Per-User IPv6 ACL for PPP Sessions
The SSO/ISSU Support for per-User IPv6 ACL for PPP Sessions feature reproduces IPv6 ACLs on the active Route Processor to the standby RP and provides a consistent stateful switchover and in-service software upgrade experience for active sessions. The feature also extends the ability to maintain Template ACLs (IPv6 only or dual stack) through ISSU and SSO.
Both named and tagged ACLs can be configured and applied in the following ways:
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Table 1 shows information about support for functionality and SSO for these ACL configurations:
Table 1
SSO Support for Named and Tagged ACLs
How to Implement Traffic Filters for IPv6 Security
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Configuring IPv6 Traffic Filtering
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Creating and Configuring an IPv6 ACL for Traffic Filtering
Restrictions
IPv6 ACLs on the Cisco ASR 1000 platform do not contain implicit permit rules. The IPv6 neighbor discovery process uses the IPv6 network-layer service; therefore, to enable IPv6 neighbor discovery, you must add IPv6 ACLs to allow IPv6 neighbor discovery packets to be sent and received on an interface. In IPv4, the Address Resolution Protocol (ARP), which is equivalent to the IPv6 neighbor discovery process, uses a separate data-link-layer protocol; therefore, by default IPv4 ACLs implicitly allow ARP packets to be sent and received on an interface.
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deny protocol {source-ipv6-prefix/prefix-length | any | host source-ipv6-address} [operator [port-number]] {destination-ipv6-prefix/prefix-length | any | host destination-ipv6-address} [operator [port-number]] [dest-option-type [doh-number | doh-type]] [dscp value] [flow-label value] [fragments] [log] [log-input] [mobility] [mobility-type [mh-number | mh-type]] [routing] [routing-type routing-number] [sequence value] [time-range name] [undetermined-transport]DETAILED STEPS
Applying the IPv6 ACL to an Interface
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Controlling Access to a vty
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Creating an IPv6 ACL to Provide Access Class Filtering
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deny protocol {source-ipv6-prefix/prefix-length | any | host source-ipv6-address} [operator [port-number]] {destination-ipv6-prefix/prefix-length | any | host destination-ipv6-address} [operator [port-number]] [dest-option-type [doh-number | doh-type]] [dscp value] [flow-label value] [fragments] [log] [log-input] [mobility] [mobility-type [mh-number | mh-type]] [routing] [routing-type routing-number] [sequence value] [time-range name] [undetermined-transport]DETAILED STEPS
Applying an IPv6 ACL to the Virtual Terminal Line
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Enabling IPv6 Template Processing
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Troubleshooting IPv6 Security Configuration and Operation
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Configuration Examples for Implementing Traffic Filters for IPv6 Security
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Example: Configuring an Access List on the Router
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Example: Route Processor Forwarding Manager ACL Configuration
Router# show running-config interface port-channel 3.2Building configuration...Current configuration : 328 bytes!interface Port-channel3.2encapsulation dot1Q 2 primary GigabitEthernet0/0/4 secondary GigabitEthernet1/2/4ip address 10.1.1.1 255.255.255.0ipv6 address 2001:DB8:1111:1111::1/64ipv6 traffic-filter OutFilter_IPv6 outipv6 nd reachable-time 180000ipv6 nd ra suppressipv6 ospf 100 area 0snmp trap link-statusendRouter# show ipv6 access-list OutFilter_IPv6IPv6 access list OutFilter_IPv6permit icmp any any mld-query sequence 30permit icmp any any router-advertisement sequence 40deny 103 any any sequence 50permit icmp any any packet-too-big sequence 60deny icmp any any sequence 70deny ipv6 2404:1A8:1100:9::/64 any sequence 74deny ipv6 2404:1A8:1100:10::/64 any sequence 75permit ipv6 any 2050::/16 log-input sequence 80deny ipv6 2404:1A8:1100:13::/64 any sequence 90deny ipv6 2404:1A8:1100:14::/64 any sequence 100deny ipv6 2408:40:2000::/35 2408:40:2000::/35 dscp default sequence 110permit ipv6 any any (3974749339 matches) sequence 120Router# show platform software access-list R0 statisticsForwarding Manager Access-list Messaging StatisticsSet Log Threshold: 0, Interval: 0IPv4 Access-list Entry Add: 1, Delete: 0IPv4 Access-list Bind: 0, Unbind: 0IPv4 Access-list Resequence: 0, Delete: 1IPv6 Access-list Entry Add: 82, Delete: 0IPv6 Access-list Bind: 3003, Unbind: 0IPv6 Access-list Resequence: 0, Delete: 0Access-list Sync Start: 0, End: 0CPP Match Add: 0, Replace: 0, ACK Success: 0, ACK Error: 0CPP Match Delete: 0, ACK Success: 0, ACK Error: 0CPP Action Edit: 0, ACK Success: 0, ACK Error: 0CPP Action Replace: 0, ACK Success: 0, ACK Error: 0CPP Bind: 0, ACK Success: 0, ACK Error: 0CPP Unbind: 0, ACK Success: 0, ACK Error: 0Router# show platform software access-list R1 name OutFilter_IPv6 ace 100Access-list: OutFilter_IPv6Access-list Entry Sequence: 100Type: Permanent, Operation: AddAction: DenyDestination Address: ::, Length: 00Source Address: 2404:1a8:1100:14::, Length: 0x24Example: Forwarding Processor Forwarding Manager ACL Configuration
Router# show platform software access-list F0 statisticsForwarding Manager Access-list Messaging StatisticsSet Log Threshold: 0, Interval: 0IPv4 Access-list Entry Add: 0, Delete: 0IPv4 Access-list Bind: 0, Unbind: 0IPv4 Access-list Resequence: 0, Delete: 1IPv6 Access-list Entry Add: 82, Delete: 0IPv6 Access-list Bind: 3003, Unbind: 0IPv6 Access-list Resequence: 0, Delete: 0Access-list Sync Start: 0, End: 0CPP Match Add: 86, Replace: 0, ACK Success: 86, ACK Error: 0CPP Match Delete: 4, ACK Success: 4, ACK Error: 0CPP Action Edit: 83, ACK Success: 83, ACK Error: 0CPP Action Replace: 0, ACK Success: 0, ACK Error: 0CPP Bind: 3003, ACK Success: 3003, ACK Error: 0CPP Unbind: 0, ACK Success: 0, ACK Error: 0Router# show platform software access-list F0 name OutFilter_IPv6 ace 100Access-list: OutFilter_IPv6Access-list Entry Sequence: 100Match Class Index: 11Epoch: 0State: DownloadedRequested Operation: No-opIssued Operation: No-opType: PermanentAction: DenyRouter# access-list F0 name OutFilter_IPv6 ace 100 max-records 20Access-list: OutFilter_IPv6Access-list Index: 2, Protocol: IPv6, Type: IPv6Security References: 2001, Classifier References: 0, Shared target: 2001Pending Download Access-list Entry: 0Pending Acknowledgements Matches: 0, Actions: 0Downloaded Access-list Entry: 12Total Access-list Entry after pending updates are processed: 12AOM object identifier: 141State: NormalNumber of Access-list Entry Shown: 3ACE Number Class Index State-------------------------------------------------------------------100 11 Downloaded110 12 Downloaded120 13 DownloadedThe following command summarizes the number of entries and references in the access list:
Router# show platform software access-list F0 summaryAccess-list Index Num Ref Num ACEs--------------------------------------------------------------------------icmp2 1 1 2OutFilter_IPv6 2 2001 12p11 3 1000 3Example: Applying an IPv6 Access List to an Interface
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Example: Route Processor Forwarding Manager ACL Application to an Interface
The following examples show how to configure and verify the Route Processor Forwarding Manager access list application to Gigabit Ethernet interface 1/0/1:
Router(config)# interface GigabitEthernet 1/0/1Router(config-if)# ip access-group test inRouter# show platform software access-list R0 statisticsForwarding Manager Access-list Messaging StatisticsSet Log Threshold: 0, Interval: 0IPv4 Access-list Entry Add: 1, Delete: 0IPv4 Access-list Bind: 0, Unbind: 0IPv4 Access-list Resequence: 0, Delete: 1IPv6 Access-list Entry Add: 82, Delete: 0IPv6 Access-list Bind: 3003, Unbind: 0IPv6 Access-list Resequence: 0, Delete: 0Access-list Sync Start: 0, End: 0CPP Match Add: 0, Replace: 0, ACK Success: 0, ACK Error: 0CPP Match Delete: 0, ACK Success: 0, ACK Error: 0CPP Action Edit: 0, ACK Success: 0, ACK Error: 0CPP Action Replace: 0, ACK Success: 0, ACK Error: 0CPP Bind: 0, ACK Success: 0, ACK Error: 0CPP Unbind: 0, ACK Success: 0, ACK Error: 0Router# show platform software access-list R0 bind interface Port-channel1.2Interface: Port-channel1.2, Index: 35, Protocol: IPv6, Direction: OutputAccess-list: OutFilter_IPv6Operation: AddExample: Forwarding Processor Forwarding Manager ACL Application to an Interface
The following examples show how to configure and verify the Forwarding Processor Forwarding Manager access list application to Gigabit Ethernet interface 1/0/1:
Router(config)# interface GigabitEthernet 1/0/1Router(config-if)# ip access-group test inRouter# show platform software access-list F0 statisticsForwarding Manager Access-list Messaging StatisticsSet Log Threshold: 0, Interval: 0IPv4 Access-list Entry Add: 0, Delete: 0IPv4 Access-list Bind: 0, Unbind: 0IPv4 Access-list Resequence: 0, Delete: 1IPv6 Access-list Entry Add: 82, Delete: 0IPv6 Access-list Bind: 3003, Unbind: 0IPv6 Access-list Resequence: 0, Delete: 0Access-list Sync Start: 0, End: 0CPP Match Add: 86, Replace: 0, ACK Success: 86, ACK Error: 0CPP Match Delete: 4, ACK Success: 4, ACK Error: 0CPP Action Edit: 83, ACK Success: 83, ACK Error: 0CPP Action Replace: 0, ACK Success: 0, ACK Error: 0CPP Bind: 3003, ACK Success: 3003, ACK Error: 0CPP Unbind: 0, ACK Success: 0, ACK Error: 0The following example provides a summary of the access list with number of entries and number of references:
Router# show platform software access-list F0 summaryAccess-list Index Num Ref Num ACEs--------------------------------------------------------------------------icmp2 1 1 2OutFilter_IPv6 2 2001 12p11 3 1000 3m1 4 1 2p1 5 0 3Example: IPv6 Template ACL Processing
In this example, the contents of ACL1 and ACL2 are the same, but the names are different:
ipv6 access-list extended ACL1 (PeerIP: 2001:1::1/64)permit igmp any 2003:1::1/64permit icmp 2002:5::B/64 anypermit udp any host 2004:1::5permit udp any host 2002:2BC::apermit icmp host 2001:BC::7 host 2003:3::7ipv6 access-list extended ACL2 (PeerIP: 2007:2::7/64)permit igmp any 2003:1::1/64permit icmp 2002:5::B/64 anypermit udp any host 2004:1::5permit udp any host 2002:2BC::apermit icmp host 2001:BC::7 host 2003:3::7The template for these ACLs is as follows:
ipv6 access-list extended Template_1permit igmp any 2003:1::1/64permit icmp 2002:5::B/64 anypermit udp any host 2004:1::5permit udp any host 2002:2BC::apermit icmp host 2001:BC::7 host 2003:3::7Example: Displaying Access List Statistics
The following example output for ACL statistics provides information about the counter aggregation and poll timer:
Router# show ipv6 access-list OutFilter_IPv6IPv6 access list OutFilter_IPv6permit icmp any any mld-query sequence 30permit icmp any any router-advertisement sequence 40deny 103 any any sequence 50permit icmp any any packet-too-big sequence 60deny icmp any any sequence 70deny ipv6 2001:DB8:1100:9::/64 any sequence 74deny ipv6 2001:DB8:1100:10::/64 any sequence 75permit ipv6 any 2050::/16 log-input sequence 80deny ipv6 2001:DB8:1100:13::/64 any sequence 90deny ipv6 2001:DB8:1100:14::/64 any sequence 100deny ipv6 2001:DB8:2000::/35 2408:40:2000::/35 dscp default sequence 110permit ipv6 any any (175392444 matches) sequence 120Additional References
Related Documents
Basic IPv6 configuration
"Implementing IPv6 Addressing and Basic Connectivity," Cisco IOS XE IPv6 Configuration Guide
IPv6 supported feature list
"Start Here: Cisco IOS XE Software Release Specifics for IPv6 Features," Cisco IOS XE IPv6 Configuration Guide
Stateful Switchover
In Service Software Upgrade
IPv6 commands: complete command syntax, command mode, defaults, usage guidelines, and examples
Cisco IOS master command list, all releases
Standards
No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature.
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MIBs
None
To locate and download MIBs for selected platforms, Cisco software releases, and feature sets, use Cisco MIB Locator found at the following URL:
RFCs
Technical Assistance
Feature Information for Implementing Traffic Filters for IPv6 Security
Table 2 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 2 Feature Information for Implementing Traffic Filters for IPv6 Security
IPv6 Services—Extended Access Control Lists
Cisco IOS XE Release 2.1
Standard IPv6 ACL functionality was extended to support traffic filtering based on IPv6 option headers and optional, upper-layer protocol type information for finer granularity of control.
The following sections provide information about this feature:
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The following commands were modified by this feature: clear ipv6 access-list, clear ipv6 inspect, clear ipv6 prefix-list, deny, ipv6 access-class, ipv6 access-list, ipv6 traffic-filter, line, permit, show ipv6 access-list.
IPv6 Services—Standard Access Control Lists
Cisco IOS XE Release 2.1
Access lists determine what traffic is blocked and what traffic is forwarded at router interfaces and allow filtering based on source and destination addresses, inbound and outbound to a specific interface.
The following sections provide information about this feature:
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The following commands were modified by this feature: clear ipv6 access-list, clear ipv6 inspect, clear ipv6 prefix-list, deny, ipv6 access-class, ipv6 access-list, ipv6 traffic-filter, line, permit, show ipv6 access-list.
IPv6 ACL—Template ACL
Cisco IOS XE Release 3.2S
This feature allows similar per-user IPv6 ACLs to be replaced by a single template ACL.
The following sections provide information about this feature:
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The following commands were modified by this feature: access-list template, show access-list template.
SSO/ISSU Support for Per-User IPv6 ACL for PPP Sessions
Cisco IOS XE Release 3.2.1S
Reproducing IPv6 ACLs on the active RP to the standby RP provides a consistent SSO and ISSU experience for active sessions. The following section provides information about this feature:
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Any Internet Protocol (IP) addresses used in this document are not intended to be actual addresses. Any examples, command display output, and figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses in illustrative content is unintentional and coincidental.
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