Depends. This router isn't running BCP-38 as it's run at our borders. Looking at the specs. Firewall rules do take it out of fastpath. Which means it's going to take a decent performance hit on paper. I'm not sure if their auto method of enabling BCP-38 IE. the IP>Settings>RP Filter method would accomplish the same outcome, Without taking the router out of fastpath. I assume it works the same as using firewall rules. Just "Behind the scenes". That being said, Real world testing. Running the traffic levels I mentioned before. I put a single simple firewall rule on the router. Which effectively took it out of fastpath. And also enabled connection tracking. I saw no noticeable change in CPU load. Nick Olsen Network Operations (855) FLSPEED x106 ---------------------------------------- From: "Hal Murray" <hmurray@megapathdsl.net> Sent: Friday, December 27, 2013 2:38 PM To: nanog@nanog.org Cc: "Hal Murray" <hmurray@megapathdsl.net> Subject: Re: Mikrotik Cloud Core Router and BGP real life experiences? nanog-request@nanog.org said:

We replaced a few Maxxwave 6 port Atom's with the CCR. ~400Mb/s and ~40K pps aggregate across all ports. CPU load went from ~25% to ~0-2%. These are in a configuration where they have little or no firewall/nat/queue rules. And in most cases are running MPLS.

How much CPU does it take to implement BCP-38? -- These are my opinions. I hate spam.