The communications server is not configured to use PPP encapsulation and PPP authentication CHAP for the async or AUX port used for dial in.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-17840	NET1615	SV-19115r1_rule		Medium

Description
A communications server (aka terminal server) can be used to provide interconnectivity between all managed network elements and the OOBM gateway router for administrative access to the device’s console port. In the event the OOBM network is not able to provide connectivity due to an outage, the communications server can provide a dial-up PPP connection to access a network element. The auxiliary port, consol port, as well as any slow-speed async serial port with an analog modem connected to the managed device also provides the capability for direct dial-up administrative access for infrastructures that do not have a communications server for management access.

Description

A communications server (aka terminal server) can be used to provide interconnectivity between all managed network elements and the OOBM gateway router for administrative access to the device’s console port. In the event the OOBM network is not able to provide connectivity due to an outage, the communications server can provide a dial-up PPP connection to access a network element. The auxiliary port, consol port, as well as any slow-speed async serial port with an analog modem connected to the managed device also provides the capability for direct dial-up administrative access for infrastructures that do not have a communications server for management access.

STIG	Date
Network Devices Security Technical Implementation Guide	2016-09-28

Details

Check Text ( C-19324r1_chk )
Step 1: Issue the show line command to see the AUX port tty numbering for the communications server. The numbering varies based on the router model and modules installed. Step 2: Review the communications server configuration and verify that CHAP is used for PPP authentication. Assuming that line 4 is bound to the AUX port, the configuration would look similar to the example shown below: interface async 4 encapsulation ppp ppp authentication chap

Check Text ( C-19324r1_chk )

Step 1: Issue the show line command to see the AUX port tty numbering for the communications server. The numbering varies based on the router model and modules installed.

Step 2: Review the communications server configuration and verify that CHAP is used for PPP authentication. Assuming that line 4 is bound to the AUX port, the configuration would look similar to the example shown below:

interface async 4
encapsulation ppp
ppp authentication chap

Fix Text (F-17767r1_fix)
Configure the communications server to use PPP encapsulation and PPP authentication CHAP for the async or AUX port used for dial in.