STIGQter STIGQter: STIG Summary: Cisco IOS XR Router RTR Security Technical Implementation Guide Version: 3 Release: 3 Benchmark Date: 01 Oct 2025:

The Cisco perimeter router must be configured to drop IPv6 packets containing a Hop-by-Hop or Destination Option extension header with an undefined option type.

DISA Rule

SV-230160r1132543_rule

Vulnerability Number

V-230160

Group Title

SRG-NET-000364-RTR-000206

Rule Version

CISC-RT-000398

Severity

CAT II

CCI(s)

Weight

10

Fix Recommendation

Configure the router to drop all inbound IPv6 packets containing option type values regardless of whether they appear in a Hop-by-Hop or Destination Option header as shown in the example below.


RP/0/0/CPU0:R3(config)# ipv6 access-list FILTER_IPV6
RP/0/0/CPU0:R3(config-ipv6-acl)# deny 60 any any dest-option log
RP/0/0/CPU0:R3(config-ipv6-acl)# deny hbh any any dest-option log
RP/0/0/CPU0:R3(config-ipv6-acl)# permit ipv6 …
…
…
…
RP/0/0/CPU0:R3(config-ipv6-acl)# deny ipv6 any any log
RP/0/0/CPU0:R3(config-ipv6-acl)# exit
RP/0/0/CPU0:R3(config)# interface gigabitethernet 0/2/0/2
RP/0/0/CPU0:R3(config-if)# ipv6 access-group FILTER_IPV6 ingress
RP/0/0/CPU0:R3(config-if)# end

Check Contents

This requirement is not applicable for the DODIN Backbone.

Review the router configuration and determine if filters are bound to the applicable interfaces to drop all inbound IPv6 packets containing an undefined option type value regardless of whether they appear in a Hop-by-Hop or Destination Option header. Undefined values are 0x02, 0x03, 0x06, 0x9 – 0xE, 0x10 – 0x22, 0x24, 0x25, 0x27 – 0x2F, and 0x31 – 0xFF.

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

interface interface gigabitethernet 0/2/0/2
ipv6 address 2001::1:0:22/64
ipv6 access-group FILTER_IPV6 ingress

Step 2: Verify that the ACL drops IPv6 packets containing Hop-by-Hop or Destination Option extension headers as shown in the example below.

ipv6 access-list FILTER_IPV6
10 deny 60 any any dest-option log
20 deny hbh any any dest-option log
30 permit …
…
…
…
90 deny ipv6 any any log


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

If the router is not configured to drop IPv6 packets containing a Hop-by-Hop or Destination Option extension headers with destination options, this is a finding.

Vulnerability Number

V-230160

Documentable

False

Rule Version

CISC-RT-000398

Severity Override Guidance

This requirement is not applicable for the DODIN Backbone.

Review the router configuration and determine if filters are bound to the applicable interfaces to drop all inbound IPv6 packets containing an undefined option type value regardless of whether they appear in a Hop-by-Hop or Destination Option header. Undefined values are 0x02, 0x03, 0x06, 0x9 – 0xE, 0x10 – 0x22, 0x24, 0x25, 0x27 – 0x2F, and 0x31 – 0xFF.

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

interface interface gigabitethernet 0/2/0/2
ipv6 address 2001::1:0:22/64
ipv6 access-group FILTER_IPV6 ingress

Step 2: Verify that the ACL drops IPv6 packets containing Hop-by-Hop or Destination Option extension headers as shown in the example below.

ipv6 access-list FILTER_IPV6
10 deny 60 any any dest-option log
20 deny hbh any any dest-option log
30 permit …
…
…
…
90 deny ipv6 any any log


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

If the router is not configured to drop IPv6 packets containing a Hop-by-Hop or Destination Option extension headers with destination options, this is a finding.

Check Content Reference

M

Target Key

4029