STIGQter: STIG Summary: Cisco IOS Switch RTR Security Technical Implementation Guide Version: 3 Release: 3 Benchmark Date: 01 Apr 2026:

The Cisco perimeter switch must be configured to drop IPv6 packets containing the NSAP address option within Destination Option header.

DISA Rule

SV-237775r1132548_rule

Vulnerability Number

V-237775

Group Title

SRG-NET-000364-RTR-000205

Rule Version

CISC-RT-000397

Severity

CAT II

CCI(s)

• CCI-002403 - Only allow incoming communications from organization-defined authorized sources routed to organization-defined authorized destinations.

Weight

10

Fix Recommendation

Configure the switch to drop IPv6 packets containing a Destination Option header as shown in the example below.

SW1(config)#ipv6 access-list FILTER_IPV6
SW1(config-ipv6-acl)#deny 60 any any dest-option log
SW1(config-ipv6-acl)#permit …
…
…
…
SW1(config-ipv6-acl)#deny ipv6 any any log
SW1(config-ipv6-acl)#exit
SW1(config)#int g1/0
SW1(config-if)#ipv6 traffic-filter FILTER_IPV6
SW1(config-if)#end

Check Contents

This requirement is not applicable for the DODIN Backbone.

Review the switch configuration and determine if filters are bound to the applicable interfaces to drop IPv6 packets containing a Destination Option header with option type value of 0xC3 (NSAP address).

Step 1: Verify that an inbound IPv6 ACL has been configured on the external interface.

interface gigabitethernet1/0
ipv6 address 2001::1:0:22/64
ipv6 traffic-filter FILTER_IPV6 in


Step 2: Verify that the ACL drops IPv6 packets containing a Destination Option header as shown in the example below.

ipv6 access-list FILTER_IPV6
deny 60 any any dest-option log
permit ipv6 …
…
…
…
deny ipv6 any any log

Note: Cisco has deprecated the dest-option-type command used to filter by option type within the Destination Option header. Therefore, all packets with the Destination Option header must be dropped.

If the switch is not configured to drop IPv6 packets containing a Destination Option header, this is a finding.

Vulnerability Number

V-237775

Documentable

False

Rule Version

CISC-RT-000397

Severity Override Guidance

This requirement is not applicable for the DODIN Backbone.

Review the switch configuration and determine if filters are bound to the applicable interfaces to drop IPv6 packets containing a Destination Option header with option type value of 0xC3 (NSAP address).

Step 1: Verify that an inbound IPv6 ACL has been configured on the external interface.

interface gigabitethernet1/0
ipv6 address 2001::1:0:22/64
ipv6 traffic-filter FILTER_IPV6 in


Step 2: Verify that the ACL drops IPv6 packets containing a Destination Option header as shown in the example below.

ipv6 access-list FILTER_IPV6
deny 60 any any dest-option log
permit ipv6 …
…
…
…
deny ipv6 any any log

Note: Cisco has deprecated the dest-option-type command used to filter by option type within the Destination Option header. Therefore, all packets with the Destination Option header must be dropped.

If the switch is not configured to drop IPv6 packets containing a Destination Option header, this is a finding.

Check Content Reference

M

Target Key

4065