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

The Cisco switch must be configured to disable the auxiliary port unless it is connected to a secured modem providing encryption and authentication.

DISA Rule

SV-220439r1137906_rule

Vulnerability Number

V-220439

Group Title

SRG-NET-000019-RTR-000001

Rule Version

CISC-RT-000230

Severity

CAT III

CCI(s)

• CCI-001414 - Enforce approved authorizations for controlling the flow of information between connected systems based on organization-defined information flow control policies.

Weight

10

Fix Recommendation

Disable the auxiliary port.

SW2(config)#line aux 0
SW2(config-line)#no exec
SW2(config-line)#transport input none

Check Contents

Review the configuration and verify that the auxiliary port is disabled unless a secured modem providing encryption and authentication is connected to it.

line aux 0
no exec

Note: transport input none is the default; hence, it will not be shown in the configuration.

If the auxiliary port is not disabled or is not connected to a secured modem when it is enabled, this is a finding.

Vulnerability Number

V-220439

Documentable

False

Rule Version

CISC-RT-000230

Severity Override Guidance

Review the configuration and verify that the auxiliary port is disabled unless a secured modem providing encryption and authentication is connected to it.

line aux 0
no exec

Note: transport input none is the default; hence, it will not be shown in the configuration.

If the auxiliary port is not disabled or is not connected to a secured modem when it is enabled, this is a finding.

Check Content Reference

M

Target Key

4065