The Nokia router must be configured to have Internet Control Message Protocol (ICMP) mask replies disabled on all external interfaces.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-283852 | NOKI-RT-000340 | SV-283852r1203805_rule | CCI-002385 | medium |
| Description | ||||
| 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. Mask Reply ICMP messages are commonly used by attackers for network mapping and diagnosis. | ||||
| STIG | Date | |||
| Nokia Service Router OS 25.x Router Security Technical Implementation Guide | 2026-06-15 | |||
Details
Check Text (C-283852r1203805_chk)
Review the device configuration to determine if controls have been defined to ensure the router does not send ICMP Mask Reply messages out to any external interfaces.
Use the command below to verify "ICMP Mask Reply" is set to "False":
- show router interface "TO-PE1" detail | match "ICMP Mask Reply"
ICMP Mask Reply : False
If ICMP Mask Reply messages are enabled on any external interfaces, this is a finding.
Fix Text (F-88322r1203804_fix)
Disable ICMP mask replies on all external interfaces, as shown in the example below:
- configure router interface "TO-PE1" icmp no mask-reply