we are trying to migrate a cisco 3750 L3 switch to a CRS226-24G-2S+. The cisco device has 12 ports active, some of them are vlan interfaces and some routed interfaces with just a default route point to our main router. The CPU usage plays at around 35-40 percent.
When we try to migrate some links on the cisco device to mikrotik. The Mikrotik CPU goes pretty high ranging from 40-70 percent. We have just transfered 3 links and its running high on CPU usage. My firewall rules are just 3 lines.
I did a profile test to see what consumes the CPU.
mostly idle, management and networking.
mikrotik CPU.png
profile.png
Is the CRS designed for L3 purposes or just plain L2?
As it onloy has a 400MHz CPU, I think it is designed to handle a modest amount of L3 traffic, but certainly not for all ports at full wirespeed, especially if firewall rules come into play.
IMHO, the naming “Cloud Router Switch” is more a marketing thing than an appropriate product description.
all current CRS boxes have 1Gbps internal link from the switch chip towards the CPU which performs routing.
thus all the L3 performance will be limited to 1Gbps. and this is the theoretic maximum.
if you add fw rules, you put more load on the cpu, and in this case it’s not the bandwidth, but the forwarding rate is the issue.
as you see on the lower graph, even w/o fw rules the max forwarding rate is 24kpps.
if you do the math, 24k1500bytes8bits = 288.000.000bps = 288Mbps
so this is the maximum you can squeeze out from this platform if you route.
i’ve heard of some plans, that will enable the switch chip to perform static routing w/o the cpu,
but that was like 6-8 months ago, and there wasn’t no word about it since then.
CRS226 is a great GE port extender if you use a 10G-based CCR for routing.