I'm having issues with my router acting very slow (Adtran Netvanta 3458). We have two networks, let's call them A and B. When I run netperf from two servers on network A (no routing) I get speeds along the lines of 900 Mbps. Which makes sense, since we have all 1Gbps switches. When testing A to B (or vice-versa) I get speeds along the lines of 22Mbps. I have also tested connecting my laptop to the switchports on the router, and testing two servers on network A (no routing) and got speeds around 90 Mbps. Which makes sense since the switchports on the router are 100Mbps. Does anyone have any idea why routing would be so slow?

We bought the router over a year ago, and we think it has been doing this since then, but we never actually tested it before. (network B isn't really used much, so we didn't notice much) We were implementing a site-to-site VPN and noticed it was ridiculously slow, so we started testing basic routing performance. I have ruled out cabling and router CPU/memory utilization. Adtran looked at my config, but didn't see anything wrong with it.