lots of lost packets after migrate to Prisma SD-WAN

[Sabjul]

Hi, (sorry for me English, i'm french)

We have finalized our migration to Prisma SD-WAN, and since we have 80% of our sites reporting problems to us, 
we have noticed that there is a high percentage of lost packets.
when we use this command directly on the interface debug bw-test src-interface destination= the pourcentage of lost packets is around 80%
so it's strange with this pourcentage working seems to be impossible.
In the Console we see on the same site (in the tunnel) 25-30% of lost packets.
What we can do to find what equipment drop packets or parameter to change. With our old sdwan solution everything was ok.
Best regards,

[kn]

Hi Sabjul, 

Do you see any interface drops, you can check this under Monitor >>Activity >> system and then select site and wan interface where you facing packet loss. Also please try to see if ISP needs specific speed/duplex/MTU  settings. 

[eouko]

Could you check transmission IP Path CRC errors, including path MTU settings?

[JeroenvE]

This could be MTU issues, if your old solution had less encapsulation overhead. I haven't played around with settings, but there's an MTU option under the interface settings you could play around with.

Also, check what traffic is lost. I've seen traffic in my network being blackholed because the flow got stuck in an invalid state but was never deleted because traffic kept coming. This was specifically udp and can be avoided by changing the timeouts in the application settings.