Tunnel performance

RouterOS General
1

Hey,

Running into an issue. We have some routers at some remote sites that can run a MT bandwidth test between each other at near gigabit speed using TCP, however anything over a tunnel (IP-IP, GRE, EoIP, no IPSec) will only test out at 300mbps or so. The test is being run from the router on one end to the router on the other end using the tunnel interface IPs.

Neither side (CCRs and/or CHR) is showing 100% CPU load. Profile doesn’t indicate any single core is maxed out.

I’m expecting some performance loss with the lower MTU across the tunnel, but not a 60% reduction. Am I missing anything here?

2

Hey
It’s a discouraged practice to perform bandwidth tests involving the subjects themselves for load generation; meaning have other instances, not the routers, do the load test.
Also, as you hinted, a tunnel will have lower mtu. that should be accounted for at source and target, to avoid fragmentation in routers / at tunnel entry.