Hoi,
On Tue, Mar 12, 2024 at 3:03 AM Embedded <li...@optimcloud.com> wrote:
On Monday 11 March 2024 07:26:07 PM (+07:00), Dave Taht wrote:
> He also did a nice writeup of an inexpensive 32x100Gbit switch
> recently, running... debian.
>
>
https://www.linkedin.com/pulse/debian-mellanox-100g-switch-pim-van-pelt-3pivf/
<https://www.linkedin.com/pulse/debian-mellanox-100g-switch-pim-van-pelt-3pivf/>
Yupp great write up, though curious why he didnt just use sonic-vpp
as it already exist
This is actually a really good question (although off-topic) so I
thought I'd get to this answer separately.
There are two reasons why I would not use sonic-vpp on this Mellanox
family of switches, one is functional and the other is architechtural.
1) Sonic VPP makes the VPP dataplane available for a subset of very well
defined YANG models and APIs. As with merchant silicon, the VPP
dataplane on x86_64/amd64 (and possibly arm64) would be able to do the
fast routing and switching, much like the silicon would. However, VPP
has an incredibly rich feature set, only very few things are supported
in Sonic VPP. In fact, several key features I use are not available in
Sonic, nor Sonic VPP (MPLS L2VPN, GENEVE, ERSPAN).
As such, moving away from the lower level offering will give me an
appliance with predictable and (mostly) interchangeable semantics, but
it will lose me a tonne of functionality.
2) The Mellanox SN2700 (and other siblings in this series) have a very
modest Atom based CPU on the Linux side. The one I wrote about has a two
core Celeron(R) CPU 1047UE @ 1.40GHz. It's tiny, and would not perform
very well running VPP at all. Besides the CPU, VPP does not program the
Spectrum ASIC at all -- it is not even aware of it. So the way to make
this work, would be to 'trap' all the traffic from the ASIC on ingress,
and forward it over the PCIe bus to these CPUs, and have VPP send them
back over the PCIe bus to the ASIC for egress. I noticed that the
Spectrum chip is connected with x4 PCIe v3.0 so the throughput would be
terrible.
But despite that, it just means 'VPP is not a good fit'. Sonic itself,
has a build specifically for Spectrum:
https://github.com/sonic-net/SONiC/blob/sonic_image_md_update/supported_devices_platforms.md
So one might just run 'Sonic-Mellanox' on them! For me: Debian,
ifupdown2, and Bird2 are all I need. KISS, and I get to maintain these
switches in mostly the same way as any other hypervisor or VM.
groet,
Pim
--
Pim van Pelt<p...@ipng.ch>
PBVP1-RIPE -https://ipng.ch/
_______________________________________________
Babel-users mailing list
Babel-users@alioth-lists.debian.net
https://alioth-lists.debian.net/cgi-bin/mailman/listinfo/babel-users
