inter-VLAN packet loss

Hi!

We are experiencing 2-4% inter-VLAN packet loss.

ping 192.168.8.56 -c 600 -s 65500
600 packets transmitted, 578 received, 3% packet loss, time 602870ms

Router: RB1100AHx2
Configuration:

  • RouterOS 6.35.4
  • two interfaces in 802.3ad bond
  • 8 VLANs and 8 VRRP addresses configured
  • 27 routes
  • 2 OpenVPN connections
  • 1 IPIP+IPsec connection
  • OSPF
  • 30 firewall rules matched with address lists
  • fasttrack enabled

Load:

  • CPU: from 40%-60%
  • Memory: ~25%
  • Bandwidth: 100mbit average / 35000 pps

Could someone please point me in the right direction?