CISC-RT-000740 - The Cisco PE switch must be configured with Unicast Reverse Path Forwarding (uRPF) loose mode enabled on all CE-facing interfaces.

Information

The uRPF feature is a defense against spoofing and denial-of-service (DoS) attacks by verifying if the source address of any ingress packet is reachable. To mitigate attacks that rely on forged source addresses, all provider edge switches must enable uRPF loose mode to guarantee that all packets received from a CE switch contain source addresses that are in the route table.

NOTE: Nessus has provided the target output to assist in reviewing the benchmark to ensure target compliance.

Solution

Configure uRPF loose mode on all CE-facing interfaces as shown in the example below:

SW1(config)# int e1/2
SW1(config-if)# ip verify unicast source reachable-via any
SW1(config-if)# end

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_Cisco_NX-OS_Switch_Y24M07_STIG.zip

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-7a., CAT|II, CCI|CCI-001097, Rule-ID|SV-221127r999736_rule, STIG-ID|CISC-RT-000740, STIG-Legacy|SV-111073, STIG-Legacy|V-101969, Vuln-ID|V-221127

Plugin: Cisco

Control ID: aecf74d162b39f3bb329981b8f8818eb7b4ed83b100ddcf66786560966ba231f