The NSX Tier-0 Gateway router must be configured to have Internet Control Message Protocol (ICMP) redirects 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. Redirect 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-263307r977688_rule
- Severity
- Medium
- References
- Updated
Remediation - Manual Procedure
To configure a shared rule to drop ICMP unreachable messages, do the following:
From the NSX Manager web interface, go to Security >> Policy Management >> Gateway Firewall >> All Shared Rules.
Click "Add Rule" (add a policy first if needed). Under "Services", select "ICMP Redirect", and then click "Apply".