I'm having trouble finding documentation about interface queues, but I found that they can make a shocking difference in performance. So shocking that I almost wrote off a new CRS210 as useless...
So I bought a new CRS210 and configured it as a home router with one ether port taken out of the switch to masquerate nat an internet connection. The internet connection is 150 megabit, but the CRS was only able to forward 50 meg, and the CPU sat at 100% when this limit was reached. I was shocked that the CRS was performing so badly so I checked the forums. I found a suggestion here
to change the interface queue type from only-hardware to ethernet-default. I did this and now I am able to get the full 150+ megabit and the cpu is not spiking to 100%. I'm also seeing the same performance boost when I try this on other mips routerboards I has previously written off as too outdated for faster internet connections.
So long story, but I have a few questions:
1. Why aren't ethernet interfaces set to ethernet-default by default??
2. Is there any disadvantage to using ethernet-default, and should it be set on slave ports?