Cisco IOS XE Router RTR STIG Version Comparison

Cisco IOS XE Router RTR Security Technical Implementation Guide

Comparison

There are 17 differences between versions v1 r4 (July 24, 2020) (the "left" version) and v2 r2 (April 23, 2021) (the "right" version).

Check CISC-RT-000235 was added to the benchmark in the "right" version.

This check's original form is available here.

Text Differences

Title

The Cisco router must be configured to have Cisco Express Forwarding enabled.

Check Content

Review the router to verify that CEF is enabled. IPv4 Example: ip cef IPv6 Example: ipv6 cef

Discussion

The Cisco Express Forwarding (CEF) switching mode replaces the traditional Cisco routing cache with a data structure that mirrors the entire system routing table. Because there is no need to build cache entries when traffic starts arriving for new destinations, CEF behaves more predictably when presented with large volumes of traffic addressed to many destinations—such as a SYN flood attacks that. Because many SYN flood attacks use randomized source addresses to which the hosts under attack will reply to, there can be a substantial amount of traffic for a large number of destinations that the router will have to handle. Consequently, routers configured for CEF will perform better under SYN floods directed at hosts inside the network than routers using the traditional cache.

Fix

Enable CEF IPv4 Example: ip cef IPv6 Example: ipv6 cef