I'd have thought that activating the server-side Broadband Firewall would reduce, not increase, the load on my router. But after switching on the firewall a couple of days ago, I'm now getting a stream of packet rejections showing in the router's log for
Packet invalid in connection (Invalid tcp flags for current tcp state)
What's quite odd is that all the source IPs look kosher, from Akamai, Amazon, Google, Microsoft and so forth. So I'm a bit concerned that wanted traffic is being stopped, or slowed, by false positives, besides the extra load on the router. If the Broadband Firewall is going to be counterproductive I'll turn it off again.