Control Plane Protection – part 1, trivial attack.

How many of you use the control plane protection features given by the vendor with the benefit of inventory? From what I see mostly, it is a very rare practice to use CoPP. Most of the network engineers haven’t even heard of it. “Because my network performs well, why should I care about control plane protection?” I need to start with a few words about what a control plane (CP) is.

CP is the area of device logic responsible for taking decisions, processing protocols (routing, switching), respond to requests (i.e. icmp echo reply), shortly CP is like the brain of the device (you can also think of CP as CPU – in some reason this makes sense). As now it is becoming clear, we have something important to lose when CP is not properly protected.

I will give you a quick example. Having high-end well known platform Catalyst 6509 of Cisco as the stable core of the network and any other device / pc which can generate ICMP packets, I will show you how quickly the core can become weak and unstable.

Let’s craft ICMP packet by sending a large PING (ICMP echo 8 0) (an attack similar to “Ping of Death” some say)

Dev1# ping 10.197.255.1 repeat 10000 time 1 size 12000

Observe then our high-end platform CPU usage:

CORE1#sh processes cpu history

Just look at that, we cause the CORE platform to utilize the CPU up to 97% sending only 12000 size PING packet. Now you can imagine what if the CORE would handle multiple BGP sessions, OSPF sessions or perform other CPU related functions simultaneously?

Note! In the next article, namely “Protect the Control Plane – part 2, CoPP.” I’m showing how to quickly prevent the cause of potential network and services damage.