👮‍♀️

CoPP

Control Plane Functions
  • Builds the routing and forwarding tables for the data planes
  • Runs on the process level
  • Shares the main CPU with the slow data path processes and management processes
  • By default, also shares the path (queue) to the main CPU
Threats,
  • Slow path denial-of-service attacks
  • Routing protocol spoofing
CoPP,
  • permits or denies access to the control plane
  • rate-limits access to the control plane
  • Configured as a service policy on a virtual control plane interface

1) ACLs to identify the traffic flows seen by the control plane

ip access-listed extended ICMP-CoPP
	permit icmp any any echo-reply
	permit icmp any any echo
	
ip access-listed extended IPSec-CoPP
	permit udp any eq isakmp any eq isakmp
	permit esp any any
	permit gre any any
	
ip access-listed extended Mgmt-CoPP
	permit tcp any any eq www
	permit tcp any any eq 443
	permit tcp any any eq telnet
	permit tcp any any eq 22
	permit udp any any eq snmp
	
ip access-listed extended Routing-CoPP
	permit tcp any eq bgp any established
	permit eigrp any host 224.0.0.10
	permit ospf any host 224.0.0.5
	permit ospf any host 224.0.0.6

2) Match the ACLs to class maps

class-map match-all ICMP-CoPP-MAP
	match access-group name ICMP-CoPP
	
class-map match-all IPSec-CoPP-MAP
	match access-group name IPSec-CoPP
	
class-map match-all Mgmt-CoPP-MAP
	match access-group name Mgmt-CoPP
	
class-map match-all Routing-CoPP-MAP
	match access-group name Routing-CoPP

3) Define a policy map to police traffic classes

policy-map CoPP-POLICY
	class ICMP-CoPP-MAP
		police 8000 confirm-action transmit exceed-action drop
	class IPSec-CoPP-MAP
		police 64000 confirm-action transmit exceed-action drop	
	class Mgmt-CoPP-MAP
		police 64000 confirm-action transmit exceed-action drop	
	class Routing-CoPP-MAP
		police 128000 confirm-action transmit exceed-action drop	
	class class-default
		police 8000 confirm-action transmit exceed-action drop

4) Apply the policy map to control plane as a service policy

control-plane
	service-policy input CoPP-POLICY

CoPP Verification

show policy-map control-plane