The Cisco PE switch must be configured to block any traffic that is destined to the IP core infrastructure.
An XCCDF Rule
Description
<VulnDiscussion>IP addresses can be guessed. Core network elements must not be accessible from any external host. Protecting the core from any attack is vital for the integrity and privacy of customer traffic as well as the availability of transit services. A compromise of the IP core can result in an outage or, at a minimum, non-optimized forwarding of customer traffic. Protecting the core from an outside attack also prevents attackers from using the core to attack any customer. Hence, it is imperative that all switches at the edge deny traffic destined to any address belonging to the IP core infrastructure.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>
- ID
- SV-221047r622190_rule
- Severity
- High
- References
- Updated
Remediation - Manual Procedure
Configure protection for the IP core to be implemented at the edges by blocking any traffic with a destination address assigned to the IP core infrastructure.
Step 1: Configure an ingress ACL to discard and log packets destined to the IP core address space.
SW2(config)#ip access-list extended BLOCK_TO_CORE
SW2(config-ext-nacl)#deny ip any 10.1.x.0 0.0.255.255 log-input