The Cisco router must be configured to implement message authentication for all control plane protocols.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-96857	CISC-RT-000020	SV-105995r3_rule		Medium

Description
A rogue router could send a fictitious routing update to convince a site's perimeter router to send traffic to an incorrect or even a rogue destination. This diverted traffic could be analyzed to learn confidential information about the site's network, or used to disrupt the network's ability to communicate with other networks. This is known as a "traffic attraction attack" and is prevented by configuring neighbor router authentication for routing updates. This requirement applies to all IPv4 and IPv6 protocols that are used to exchange routing or packet forwarding information; this includes all Interior Gateway Protocols (such as OSPF, EIGRP, and IS-IS) and Exterior Gateway Protocols (such as BGP), MPLS-related protocols (such as LDP), and multicast-related protocols.

Description

A rogue router could send a fictitious routing update to convince a site's perimeter router to send traffic to an incorrect or even a rogue destination. This diverted traffic could be analyzed to learn confidential information about the site's network, or used to disrupt the network's ability to communicate with other networks. This is known as a "traffic attraction attack" and is prevented by configuring neighbor router authentication for routing updates. This requirement applies to all IPv4 and IPv6 protocols that are used to exchange routing or packet forwarding information; this includes all Interior Gateway Protocols (such as OSPF, EIGRP, and IS-IS) and Exterior Gateway Protocols (such as BGP), MPLS-related protocols (such as LDP), and multicast-related protocols.

STIG	Date
Cisco IOS XE Router RTR Security Technical Implementation Guide	2020-06-30

Details

Check Text ( C-95693r1_chk )
Review the router configuration. Verify that neighbor router authentication is enabled for all routing protocols. The configuration examples below depicts OSPF, EIGRP, IS-IS and BGP authentication. BGP Example: router bgp nn no synchronization bgp log-neighbor-changes neighbor x.x.x.x remote-as nn neighbor x.x.x.x password xxxxxxx EIGRP Example: key chain EIGRP_KEY key 1 key-string xxxxxxx … … … interface GigabitEthernet0/0 ip address x.x.x.x 255.255.255.0 ip authentication mode eigrp 1 md5 ip authentication key-chain eigrp 1 EIGRP_KEY IS-IS Example: interface GigabitEthernet0/0 ip address x.x.x.x 255.255.255.0 ip router isis isis password xxxxxxx OSPF Example: interface GigabitEthernet0/0 ip address x.x.x.x 255.255.255.0 ip ospf authentication-key xxxxx If authentication is not enabled on all routing protocols, this is a finding.

Check Text ( C-95693r1_chk )

Review the router configuration. Verify that neighbor router authentication is enabled for all routing protocols. The configuration examples below depicts OSPF, EIGRP, IS-IS and BGP authentication.

BGP Example:

router bgp nn
no synchronization
bgp log-neighbor-changes
neighbor x.x.x.x remote-as nn
neighbor x.x.x.x password xxxxxxx

EIGRP Example:

key chain EIGRP_KEY
key 1
key-string xxxxxxx
…
…
…
interface GigabitEthernet0/0
ip address x.x.x.x 255.255.255.0
ip authentication mode eigrp 1 md5
ip authentication key-chain eigrp 1 EIGRP_KEY

IS-IS Example:

interface GigabitEthernet0/0
ip address x.x.x.x 255.255.255.0
ip router isis
isis password xxxxxxx

OSPF Example:

interface GigabitEthernet0/0
ip address x.x.x.x 255.255.255.0
ip ospf authentication-key xxxxx

If authentication is not enabled on all routing protocols, this is a finding.

Fix Text (F-102537r2_fix)
Configure authentication to be enabled for every protocol that affects the routing or forwarding tables. The example configuration commands below enables BGP, EIGRP, IS-IS, and OSPF authentication. BGP Example R1(config)#router bgp nn R1(config-router)#neighbor x.x.x.x password xxxxxx EIGRP Example R5(config)#key chain EIGRP_KEY R5(config-keychain)#key 1 R5(config-keychain-key)#key-string xxxxx R5(config-keychain-key)#exit R5(config-keychain)#exit R5(config)#int g0/0 R5(config-if)#ip authentication mode eigrp 1 md5 R5(config-if)#ip authentication key-chain eigrp 1 EIGRP_KEY R5(config-if)#end IS-IS Example R5(config)#int g0/0 R5(config-if)#isis password xxxxxx OSPF Example R5(config)#int g0/0 R5(config-if)#ip ospf authentication-key xxxxx R5(config-if)#end

Fix Text (F-102537r2_fix)

Configure authentication to be enabled for every protocol that affects the routing or forwarding tables.

The example configuration commands below enables BGP, EIGRP, IS-IS, and OSPF authentication.

BGP Example

R1(config)#router bgp nn
R1(config-router)#neighbor x.x.x.x password xxxxxx

EIGRP Example

R5(config)#key chain EIGRP_KEY
R5(config-keychain)#key 1
R5(config-keychain-key)#key-string xxxxx
R5(config-keychain-key)#exit
R5(config-keychain)#exit
R5(config)#int g0/0
R5(config-if)#ip authentication mode eigrp 1 md5
R5(config-if)#ip authentication key-chain eigrp 1 EIGRP_KEY
R5(config-if)#end

IS-IS Example

R5(config)#int g0/0
R5(config-if)#isis password xxxxxx

OSPF Example

R5(config)#int g0/0
R5(config-if)#ip ospf authentication-key xxxxx
R5(config-if)#end