The Cisco perimeter router must be configured to block all packets with any IP options.
An XCCDF Rule
Description
<VulnDiscussion>Packets with IP options are not fast switched and henceforth must be punted to the router processor. Hackers who initiate denial of service (DoS) attacks on routers commonly send large streams of packets with IP options. Dropping the packets with IP options reduces the load of IP options packets on the router. The end result is a reduction in the effects of the DoS attack on the router and on downstream routers.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>
- ID
- SV-216998r855841_rule
- Severity
- Medium
- References
- Updated
Remediation - Manual Procedure
This requirement is not applicable for the DODIN Backbone.
Configure the router to drop all packets with IP options.
R1(config)#ip access-list extended EXTERNAL_ACL
R1(config-ext-nacl)#15 deny ip any any option any-options