2 weeks until JNCIE-DC

I scheduled my JNCIE-DC attempt a few months back for end of April, purchased the official Juniper JNCIE-DC workbook, and I have hit the topics in the blueprint. I was able to complete all of the relevant labs in an EVE-NG environment with vMX and vQFX devices. But, I was unable to lab the Virtual Chassis Fabric as well as applying output traffic profiles to interfaces in the QFX Class of Service configuration. Time for some hardware!

2x QFX5110-48S

I’ll admit I am very fortunate my place of work allowed me to grab a couple of these lying around for a small VCF config. The configuration required is not lengthy, and I have plenty of experience with “regular” virtual chassis, but I still wanted to search for some possible hesitations.

What I’d really like to do is see VCF “under the hood.” As I understand it, the protocol is leveraging IS-IS routing variant. I’ve never seen the packet structure posted anywhere and I think that would be really interesting to document a pcap on… Maybe To Be Continued on that part.


Hit a roadblock, port mirroring a VCP interface is not allowed by JunOS.

root@QFX1# commit 
mgd: error: [edit forwarding-options analyzer analyzer input ingress interface vcp-255/0/48.0]
  Analyzer configuration error
    Interface type in vcp-255/0/48.0 is not valid for port-mirroring or next-hop-group config

It’s listed as one of the disallowed interfaces for port-mirroring as well here

Written on April 14, 2021