How LibVirt Networking Works - Under the Hood

This is the best link on this topic that I have found.

Lots of great pictures. Pictures are worth a thousand words.

https://www.redhat.com/en/blog/introduction-virtio-networking-and-vhost-net

Vector Packet Processing - Part II - Installing VPP

As a wrap-up to my day, I decided to take one of my CentOS7 servers, and install vpp on it.

I followed the cookbook found at this link:
https://wiki.fd.io/view/VPP/Installing_VPP_binaries_from_packages#RPMs

This link doesn't tell you how to set up the vpp repository, which is necessary to install any of the vpp packages (a yum groupinstall would have been nice for this, actually).

But the link for the repository is here:
https://my-vpp-docs.readthedocs.io/en/latest/gettingstarted/users/installing/centos.html

For convenience I included the snippet below.

$ cat /etc/yum.repos.d/fdio-release.repo
[fdio-release]
name=fd.io release branch latest merge
baseurl=https://nexus.fd.io/content/repositories/fd.io.centos7/
enabled=1
gpgcheck=0

This didn't take long to do at all. No problem installing packages, no problem starting up the vpp service.

But, it looks to me like old hardware and old network cards don't support vpp. So more work to do.

Unsupported PCI Device Errors on vpp service startup

Vector Packet Processing - Part I

Yesterday, I was reading up on something called Vector Packet Processing (VPP). I had not heard of this, nor the organization called Fd.io (pronounced Fido), which can be found at the following link: http://fd.io

Chasing links to get more up to speed, I found this article, which does a very good indoctrination on these newer networking technologies, which  have emerged to support virtualization, due to the overhead (and redundancy) associated with forwarding packets from NICs, to virtualization hosts, and into the virtual machines.

https://software.intel.com/en-us/articles/an-overview-of-advanced-server-based-networking-technologies

I like how the article progresses from the old-style interrupt processing, to OpenVSwitch (OVS), to SR-IOV, to DPDK, and then, finally, to VPP.

I am familiar with OpenVSwitch, which I came into contact with OpenStack, which had OpenVswitch drivers (and required you to install OpenVSwitch on the controller and compute nodes).

I was only familiar with SR-IOV because I stumbled upon it and took the time to read up on what it was. I think it was a virtual Palo Alto Firewall that had SR-IOV NIC Types, if I'm not mistaken. I spent some time trying to figure out if these servers I am running support SR-IOV and they don't seem to have it enabled, that's for sure. Whether they support it would take more research.

And DPDK I had read up on, because a lot of hardware vendors were including FastPath Data switches that were utilizing DPDK for their own in-house virtual switches, or using the DPDK-OpenVSwitch implementation.

But Vector Packet Processing (VPP), this somehow missed me. So I have been doing some catch-up on VPP, which I won't go into detail on in this post or share additional resources on such a large topic. But the link above to Fido is essentially touting VPP.

UPDATE:
I found this link, which is also spectacularly written:
https://www.metaswitch.com/blog/accelerating-the-nfv-data-plane

And, same blog with another link for those wanting the deep dive into VPP:
https://www.metaswitch.com/blog/fd.io-takes-over-vpp

Linux - NFLog and System Tap

Linux - NFLog and System Tap

I used nflog with iptables to count packets for a specific user (I will edit this later and add more info).

Later, I was told to investigate System Tap for this same use case, but never had time. So I'll write more about System Tap when I have time to investigate this.