nanog mailing list archives

Re: Juniper hardware recommendation


From: Sander Steffann <sander () steffann nl>
Date: Sun, 16 May 2021 23:22:32 +0200

Hi!

On Sat, 2021-05-15 at 11:38 +0300, Saku Ytti wrote:
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
account-layer2-overhead'.

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 L1.

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.

How do you normalise? Use L2 or L3 octets stats, and use the number of
packets to calculate the L2 and/or L1 overhead the stats are missing?
Or do you have a better way?

Cheers,
Sander

Attachment: signature.asc
Description: This is a digitally signed message part


Current thread: