IPv6 ACL Undetermined-Transport Support

The IPv6 ACL Undetermined-Transport Support feature helps in dropping misconfigured packets where the complete upper layer header is not present.

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 ACL Undetermined-Transport Support

  • The undetermined-transport option is supported only for Cisco Application Control Engines (ACE) with deny action and IPv6 protocol.

  • Undetermined transport is not applied on nonfirst fragment packets.

IPv6 ACL Undetermined-Transport

Unintended misconfigurations by users or malicious attacks on the network may cause operational problems for hosts on the network.

Upper layer header is placed at the end of Extended Header (EH) chain in IPv6 packet, as it described in RFC 2460. If the complete upper layer header is not present in the IPv6 packet, then the router cannot process the packet. These packets may be misconfigured, corrupted, or malicious packets.

You may choose to drop these packets using IPv6 ACL with undetermined-transport option.

Configuring IPv6 ACL Undetermined-Transport Support

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. ipv6 access-list acl-name
  4. deny ipv6 {src-addr | any } {dest-addr | any } [undetermined-transport ]
  5. 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 access-list acl-name

Example:


Device(config)# ipv6 access-list acl1

Configures IPv6 access list.

Step 4

deny ipv6 {src-addr | any } {dest-addr | any } [undetermined-transport ]

Example:


Device(config-ipv6-acl)# deny ipv6 2001:DB8:0300:0201::/32 2001:DB8:1:1::/64 undetermined-transport

Sets deny condition for an IPv6 access list as undermined transport.

Step 5

end

Example:


Device(config-ipv6-acl)# end

Returns to privileged EXEC mode.

Example: Example for IPv6 ACL Undetermined-Transport Support 

Device> enable
Device# configure terminal
Device(config)# ipv6 access-list acl1
Device(config-ipv6-acl)# deny ipv6 2001:DB8:0300:0201::/32 2001:DB8:1:1::/64 undetermined-transport
Device(config-ipv6-acl)# end

Additional References for IPv6 ACL Undetermined-Transport Support

Related Documents

Related Topic

Document Title

Cisco IOS commands

Cisco IOS Master Command List, All Releases

IP access list commands

Cisco IOS Security Command Reference

Configuring IP access lists

“Creating an IP Access List and Applying It to an Interface”

Standards and RFCs

Standards/RFCs

Title

RFC 2460

Internet Protocol, Version 6 (IPv6) Specification

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 ACL Template

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 ACL Template

Feature Name

Releases

Feature Information

IPv6 ACL Undetermined-Transport Support

Cisco IOS XE Release 3.15

The IPv6 ACL Undetermined-Transport Support feature helps in dropping misconfigured packets, where the complete upper layer header is not present.

No commands were introduced or modified.