We are trying to build experimental CHR 7 systems on HP G9 + Vmware The system will be used for the sole purpose of Routing ( BGP + OSPF ) . To reduce the latency, NICs are being set as pass-through to CHR. Everything seems fine but when we are pinging CHR-Server-1 to CHR-Server-2 with large ICMP packet size of 50,000 we get almost 15% packet loss but zero packet loss on small size packets.
We have tried over 10 different 10Gbps SFP+ NICs and 40Gbps QSFP+ NICs and we get the exact same result. Interestingly, when doing BW test, we get the 10Gbps / 35Gbps speed but it shows lots of packet loss with UDP.
As an experiment, we changed the interface queue from only-hardware-queue only to ethernet-default and surprisingly now we get 0% packet loss.
Seems like when using Pass-through, CHR can not use the hardware queue ?
When we replace these two systems with CCR2116 and connect them to the same switch, there is no packet loss and we dont need to change the Interface Queue from Hardware only.
So I am curious to know if anybody else experienced this or there is something wrong with our experimental setup ?
If we are supposed to use Interface Queue, what Queue size we should use if the traffic is going to be 10Gbps + ?
Thank you for the feedback