The Arista router must be configured to have Internet Control Message Protocol (ICMP) mask replies disabled on all external interfaces.
An XCCDF Rule
Description
<VulnDiscussion>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.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>
- ID
- SV-256033r882441_rule
- Severity
- Medium
- References
- Updated
Remediation - Manual Procedure
Step 1: Disable ICMP mask replies on all external interfaces.
ip access-group DENY_ICMP_MASK_REPLY
deny icmp any any mask-reply
permit ip any any