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V-283851

CAT II (Medium)

The Nokia router must be configured to have Internet Control Message Protocol (ICMP) redirects disabled on all external interfaces.

Rule ID

SV-283851r1203802_rule

STIG

Nokia Service Router OS 25.x Router Security Technical Implementation Guide

Version

V1R1

CCIs

CCI-002385

Discussion

The ICMP supports IP traffic by relaying information about paths, routes, and network conditions. Routers automatically send ICMP messages under a wide variety of conditions. Redirect ICMP messages are commonly used by attackers for network mapping and diagnosis.

Check Content

Review the device configuration to determine if controls have been defined to ensure the router does not send ICMP Redirect messages out to any external interfaces.

Use the command below to verify "Redirects " is set to "Disabled":

- show router interface "TO-PE1" detail | match "Redirects"
Redirects        : Disabled
Redirects        : Number - 100         Time (seconds)   - 10

If ICMP Redirect messages are enabled on any external interfaces, this is a finding.

Fix Text

Disable ICMP redirects on all external interfaces, as shown in the example below: 

- configure router interface "TO-PE1" icmp no redirects