The network element’s management interface is not configured as passive for the IGP instance deployed in the managed network.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-17823	NET0993	SV-19334r2_rule		Low

Description
The OOBM access switch will connect to the management interface of the managed network elements. The management interface can be a true OOBM interface or a standard interface functioning as the management interface. In either case, the management interface of the managed network element will be directly connected to the OOBM network. An OOBM interface does not forward transit traffic; thereby, providing complete separation of production and management traffic. Since all management traffic is immediately forwarded into the management network, it is not exposed to possible tampering. The separation also ensures congestion or failures in the managed network do not affect the management of the device. If the device does not have an OOBM port, the interface functioning as the management interface must be configured so management traffic, both data plane and control plane, does not leak into the managed network and production traffic does not leak into the management network.

Description

The OOBM access switch will connect to the management interface of the managed network elements. The management interface can be a true OOBM interface or a standard interface functioning as the management interface. In either case, the management interface of the managed network element will be directly connected to the OOBM network. An OOBM interface does not forward transit traffic; thereby, providing complete separation of production and management traffic. Since all management traffic is immediately forwarded into the management network, it is not exposed to possible tampering. The separation also ensures congestion or failures in the managed network do not affect the management of the device. If the device does not have an OOBM port, the interface functioning as the management interface must be configured so management traffic, both data plane and control plane, does not leak into the managed network and production traffic does not leak into the management network.

STIG	Date
Perimeter L3 Switch Security Technical Implementation Guide - Cisco	2018-11-28

Details

Check Text ( C-20313r4_chk )
If the managed network element is a layer 3 device, review the configuration to verify the management interface is configured as passive for the IGP instance for the managed network. Depending on the platform and routing protocol, this may simply require that the interface or its IP address is not included in the IGP configuration. The following configuration would be an example where OSPF is only enabled on all interfaces except the management interface: interface Fastethernet 0/0 description Enclave_Management_LAN ip address 10.1.1.22 255.255.255.0 ip access-group 100 in ip access-group 101 out interface Fastethernet 0/1 description to_our_PrivateNet ip address 172.20.4.2 255.255.255.0 interface Fastethernet 0/2 description to_our_ServiceNet ip address 172.20.5.2 255.255.255.0 interface Fastethernet 1/1 description to_our_DMZ ip address 172.20.3.1 255.255.255.0 ! router ospf 1 network 172.20.0.0 255.255.255.0 area 1 Note: The MPP feature has no effect on control plane traffic. Hence, the routing protocol must still be configured so that it is not enabled on the management interface.

Check Text ( C-20313r4_chk )

If the managed network element is a layer 3 device, review the configuration to verify the management interface is configured as passive for the IGP instance for the managed network. Depending on the platform and routing protocol, this may simply require that the interface or its IP address is not included in the IGP configuration. The following configuration would be an example where OSPF is only enabled on all interfaces except the management interface:

interface Fastethernet 0/0
description Enclave_Management_LAN
ip address 10.1.1.22 255.255.255.0
ip access-group 100 in
ip access-group 101 out
interface Fastethernet 0/1
description to_our_PrivateNet
ip address 172.20.4.2 255.255.255.0
interface Fastethernet 0/2
description to_our_ServiceNet
ip address 172.20.5.2 255.255.255.0
interface Fastethernet 1/1
description to_our_DMZ
ip address 172.20.3.1 255.255.255.0
!
router ospf 1
network 172.20.0.0 255.255.255.0 area 1

Note: The MPP feature has no effect on control plane traffic. Hence, the routing protocol must still be configured so that it is not enabled on the management interface.

Fix Text (F-17738r2_fix)
Configure the management interface as passive for the IGP instance configured for the managed network. Depending on the platform and routing protocol, this may simply require that the interface or its IP address is not included in the IGP configuration.