[j-nsp] dsc interface on qfx5100

[Saku Ytti]

On Fri, 12 Oct 2018 at 16:07, Niall Donaghy <niall.donaghy at geant.org> wrote:

> Yes we (large ISP) tried using dsc interfaces (MX series) to count RTBH
> traffic and found, 1) they don't count, and 2) IPv6 is unsupported for dsc.
> As with many Junos features, there is not parity between IPv4 and IPv6.
> That alone bugged us, but especially as the counters did not work, we
> abandoned dsc and just made the IPv4 RTBH sink a discard route:

I'm pretty convinced I've had filter counters work on discard
interface, but it's like 15 years ago, so I may misremember.

Being MX, you can still count the static route discard next hop.

ytti at r24.labxtx01.us.bb-re1> request pfe execute target fpc0 command
"show jnh 0 exception" |match "discard route"
discard route                      DISC( 66)            0          0
discard route IPv6                 DISC(102)            0          0
dsc ifl discard route              DISC( 96)            0          0

We're collecting all of the NPU counters and dumping them into a druid
for visual presentation with pivot.

There is some benefit using this method even if counters would work,
because this method will tell you which linecard and which NPU,
allowing you to discriminate ingress of packets to specific NPU. And
of course in any reasonable collection system, you just ignore the NPU
and LC labels and you'll get aggregate discards.

-- 
  ++ytti