4. May 26, 2016 cumulusnetworks.com 4
•Linux as a NOS Yesterday
•Linux as a NOS Today
•Linux as a NOS Tomorrow
Outline
5. Linux was pervasive even inside networking gear .. Just not as
a NOS
Linux was used to boot an ‘app’
Linux provided platform driver support
Booted the “networking application”
Every tool/application, stack behavior was re-invented, and re-
invented .. And re-invented.
Linux had issues with enterprise level operations
Primarily a host OS
• Device scale
• Protocol behavior ; ARP, LLDP, STP etc
Lacked Robust, scalable routing suite
Bridge implementation needed scale handling
cumulusnetworks.com 5
Yesterday
May 26, 2016
6. May 26, 2016 cumulusnetworks.com 6
Linux as a networking model (Is networking an APP or Infra ?)
The Linux universe
APP
Hadoop/Zookeper
Hypervisor
KVM/Xen
Docker
Mesos/Kubernetes
Kernel
Bridges/Routers/OVS
Each builds on each other and is silently
interchangeable i.e Infra
Even MSFT picked Linux for it’s cloud OS
Virtual Machines
Virtual Switches
Physical Servers
Physical Switch
Router
Today
7. Big events in 2015 in the linux
May 26, 2016 cumulusnetworks.com 7
Kernel Additions
Nftables
EBPF
TC integration
New Bridge driver
VXLAN driver enhancements
VRF
Light Weight Tunnels
• (infra for MPLS)
Link state management
Optimize IPv4 FIB lookup, route
driven congestion algorithm
selection
Switchdev support for Mellanox
Switch, DSA devices
NetCP (network coproc) driver
support
TCP fingerprinting
Userland Upgrades
Quagga
iproute2
ethtool
lldpd
libnl
ifupdown2
Today
8. So you believe the kernel will hold you back.
May 26, 2016 cumulusnetworks.com 8
Grey : Traditional
Stack
Red : Special
pathways
What is the Ratio ?
So the linux
kernel is getting
in your way ?
Today
9. Linux as a networking model
(to SAI or not to SAI .. They do not compete)
May 26, 2016 cumulusnetworks.com 9
Application interface, Portable
and maintainable apps can use
this layer
Innovation here leads to hair
pulling
Low level device interface;
Simplifies system software
developers, but only useful in the
context of the full system around it
Innovation and change here is
good
10. Linux networking – the path to completeness – atleast data
center
Bridging
New bridge model, incredible scale
Routing
VRF, MPLS, Light Weight Tunnels etc
Continuing performance improvements
Packet Processing path
eBPF, new classifiers for TC, Nftables
cumulusnetworks.com 10
Tomorrow and
Beyond
May 26, 2016
11. Linux networking – the path to completeness – atleast data
center
Bridging
New bridge model, incredible scale
Routing
VRF, MPLS, Light Weight Tunnels etc
Continuing performance improvements
Packet Processing path
eBPF, new classifiers for TC, Nftables
cumulusnetworks.com 11
Tomorrow and
Beyond
And then there is SwitchDev
Network Stack IS the Linux Kernel
Acceleration of Components with available
drivers
Your VM and Switch behave the same way
May 26, 2016