The Cisco perimeter switch must be configured to drop IPv6 undetermined transport packets.
An XCCDF Rule
Description
<VulnDiscussion>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 four port information of the packet.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>
- ID
- SV-237761r856663_rule
- Severity
- Medium
- References
- Updated
Remediation - Manual Procedure
Configure the switch to drop IPv6 undetermined transport packets as shown in the example below.
SW1(config)#ipv6 access-list FILTER_IPV6
SW1(config-ipv6-acl)#deny ipv6 any any undetermined-transport log
SW1(config-ipv6-acl)#permit ipv6 …
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