Juniper QFX10K IPFIX Gotchas
IPFIX is problematic on the Juniper QFX10K switches. Documentation is sparse, and doesn’t have a complete configuration. Behavior changes between versions in undocumented ways. Here’s a couple of things I noticed when upgrading from Junos 17.3 to 17.4. These also apply if you are running 18.4 code. I hit more problems with 18.4, and ended up rolling back to 17.4.
Big Changes in Reported Throughput
Here’s a graph showing total reported throughput for a QFX10K I upgraded:
There’s a few things going on there. First the reported traffic drops to zero after I upgraded. Then it starts coming up, after I fixed the first problem. But then after that the reported traffic is flat, and lower than it should be. Then it starts coming up again after I made the second fix.
First Problem: Chassis Sample Instance
The first configuration change I needed to add was this: set chassis fpc 0 sampling-instance sample-border, where sample-border is the name of the sampling instance I have configured under forwarding-options. This was not required with 17.3. If you don’t do it with 17.4, you won’t get any data.
Second Problem: DDoS-Protection
Some Juniper platforms implement Continue reading



