Juniper hardware recommendation

Saku Ytti saku at
Sat May 15 08:38:43 UTC 2021

Hey Michael,

> If accurate interface stats are important to you, MX’s don’t support accurate SNMP Interface Utilization, ie they don’t comply with RFC2665/3635, which seems like a fairly basic thing to do but they decided not to, and has been impactful to me in the past.  So, any SNMP monitoring of an interface will always show less utilization than what is actually occurring, possibly leading to a false sense of security, or delay in augmentation.  Would also affect usage based billing, if you do that.

Juniper has worked like this since day1 and shockingly the world
doesn't care, people really don't care for accuracy. CLI and SNMP are
both L3. If you want to report L2 'set chassis fpc N pic N

However, who decided that L2 is right? To me only L1 is right, I don't
care about L2 at all. So any system I'd use, I'd normalise the data to

Ethernet on minimum size packets
L1 - 100%
L2 -  76%
L3 -  24%

Not sure why 76 is better than 24. Both are wrong and will cause
operational confusion because people think the link is not congested.
This is extremely poorly understood even by professionals, so poorly
that people regularly think you can't get 100% utilisation, because
you can't unless you normalise stats to L1 rate.


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