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V-283871

CAT II (Medium)

The Nokia perimeter router must be configured to drop IPv6 undetermined transport packets.

Rule ID

SV-283871r1203862_rule

STIG

Nokia Service Router OS 25.x Router Security Technical Implementation Guide

Version

V1R1

CCIs

CCI-002403

Discussion

One of the fragmentation weaknesses known in IPv6 is the undetermined transport packet. This packet contains an undetermined protocol due to fragmentation. Depending on the length of the IPv6 extension header chain, the initial fragment may not contain the layer 4 port information of the packet.

Check Content

This requirement is not applicable for the DODIN Backbone. 

Review the router configuration to determine if it is configured to drop IPv6 undetermined transport packets.

Verify the IPv6 filter is applied on the interface using the command below: 

- show router interface "TO-PE2" detail | match "Ingr IPv6 Flt"
Egr IPv6 Flt     : none                 Ingr IPv6 Flt     : 40

If the router is not configured to drop IPv6 undetermined transport packets, this is a finding.

Fix Text

Configure the router to drop IPv6 undetermined transport/ first fragment packets, as shown in the example below: 

Create an IPv6 filter:

 - configure filter ipv6-filter 40 create
- config>filter>ipv6-filter# entry 10 create
- config>filter>ipv6-filter>entry$ match fragment first-only
- config>filter>ipv6-filter>entry$ action drop
- config>filter>ipv6-filter>entry$ exit all

Apply the IPv6 filter on the interface:

- configure router interface "TO-PE2" ingress filter ipv6 40