IPv6 Implementation Guide, Cisco IOS XE Release 3S
IPv6 Virtual Fragmentation Reassembly
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IPv6 Virtual Fragmentation Reassembly

Last Updated: August 1, 2012

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 at the end of this module.

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

Information About IPv6 Virtual Fragmentation Reassembly

IPv6 Virtual Fragmentation Reassembly

Fragmentation is a process of breaking down an IP datagram into smaller packets to be transmitted over different types of network media. Non-initial fragments of a fragmented IPv6 packet is used to pass through IPsec and NAT64 without any examination due to the lack of the L4 header, which usually is only available on the initial fragment. The IPv6 Virtual Fragmentation Reassembly (VFR) feature provides the ability to collect the fragments and provide L4 info for all fragments for IPsec and NAT64 features.

How to Implement IPv6 Virtual Fragmentation Reassembly

Configuring IPv6 Virtual Fragmentation Reassembly

SUMMARY STEPS

1.    enable

2.    configure terminal

3.    interface type number

4.    ipv6 virtual-reassembly [in | out] [max-reassemblies maxreassemblies] [max-fragments max-fragments] [timeout seconds] [drop-fragments

5.    exit

6.    show ipv6 virtual-reassembly interface interface-type

7.    show ipv6 virtual-reassembly features interface interface-type


DETAILED STEPS
 Command or ActionPurpose
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 gigabitethernet 3/1/1

 

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

 
Step 4
ipv6 virtual-reassembly [in | out] [max-reassemblies maxreassemblies] [max-fragments max-fragments] [timeout seconds] [drop-fragments

Example:

Router(config-if)# ipv6 virtual-reassembly max-reassemblies 32 max-fragments 4 timeout 7

 

Enables VFR on an interface.

 
Step 5
exit


Example:

Router(config-if)# exit

 

Exits interface configuration mode and places the router in global configuration mode.

  • Enter this command twice to reach privileged EXEC mode.
 
Step 6
show ipv6 virtual-reassembly interface interface-type

Example:

Router# show ipv6 virtual-reassembly interface e1/1/1

 

Displays VRF configuration and statistical information on a specific interface.

 
Step 7
show ipv6 virtual-reassembly features interface interface-type

Example:

Router# show ipv6 virtual-reassembly features

 

Displays VFR information on all interfaces or on a specified interface.

 

Configuration Example for IPv6 Virtual Fragmentation Reassembly

Example: Configuring IPv6 Virtual Fragmentation Reassembly

Router# show ipv6 virtual-reassembly interface gigabitethernet1/1/1
GigabitEthernet1/1/1: 
IPv6 Virtual Fragment Reassembly (VFR) is ENABLED(in)
Concurrent reassemblies (max-reassemblies): 64
Fragments per reassembly (max-fragments): 16
Reassembly timeout (timeout): 3 seconds
Drop fragments: OFF
Current reassembly count: 0
Current fragment count: 0
Total reassembly count: 6950
Total reassembly timeout count: 9
GigabitEthernet1/1/1: 
IPv6 Virtual Fragment Reassembly (VFR) is ENABLED(out)
Concurrent reassemblies (max-reassemblies): 64
Fragments per reassembly (max-fragments): 16
Reassembly timeout (timeout): 3 seconds
Drop fragments: OFF
Current reassembly count: 0
Current fragment count: 0
Total reassembly count: 0
Total reassembly timeout count: 0

Additional References

Related Documents

Related Topic Document Title

IPv6 addressing and connectivity

IPv6 Configuration Guide

Cisco IOS commands

Master Commands List, All Releases

IPv6 commands

IPv6 Command Reference

Cisco IOS IPv6 features

IPv6 Feature Mapping

Standards and RFCs

Standard/RFC Title

RFCs for IPv6

IPv6 RFCs

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 IPv6 Virtual Fragmentation Reassembly

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 1Feature Information for IPv6 Virtual Fragmentation Reassembly
Feature Name Releases Feature Information

IPv6 Virtual Fragmentation Reassembly

Cisco IOS XE Release 3.4S

The IPv6 VFR feature provides the ability to collect the fragments and provide L4 info for all fragments for IPsec and NAT64 features.

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Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.

© 2012 Cisco Systems, Inc. All rights reserved.