The Cisco PE router must be configured to drop all packets with any IP options.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-216993	CISC-RT-000750	SV-216993r856210_rule		Medium

Description

Packets with IP options are not fast switched and therefore 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.

STIG	Date
Cisco IOS Router RTR Security Technical Implementation Guide	2022-09-14

Details

Check Text ( C-18223r287307_chk )
Review the router configuration to determine if it will drop all packets with IP options as shown below. ip options drop If the router is not configured to drop all packets with IP options, this is a finding.

Fix Text (F-18221r287308_fix)
Configure the router to drop all packets with IP options as shown below. R4(config)#ip options drop