Linux As A Network OS Dinesh G Dutt Shrijeet Mukherjee Nolan Leake - PowerPoint PPT Presentation

Linux As A Network OS Dinesh G Dutt Shrijeet Mukherjee Nolan Leake Pradosh Mohapatra

Networking circa 2008 Flickr photo from [http://www.flickr.com/photos/duncanh1/] Linuxcon 2013 09/16/13 2

Data Centers have thrown a monkey wrench in the world of networking whether it be how networks are managed, the new technologies they have brought to the fore such as SDN or network virtualization Linuxcon 2013 09/16/13 3

Modern data center networks are based around the following ideas: New breed of applications which are L3-aware and workaround network failures IP-based networks Automated management • Configuration and monitoring • Rapid spin-up and spin-down of networks Linuxcon 2013 09/16/13 4

Operating Systems define how you manage the individual boxes and thereby the system Linuxcon 2013 09/16/13 5

Traditional Router/Switch Oses: Complex routing/switching features Structured as a black box: – No well-defined API Closed development model Antediluvian management tool chain Very slow spin-up and spin-down of networks Linuxcon 2013 09/16/13 6

Modern data centers usually run GNU/Linux as the server OS: Well established and open API Sophisticated management tool chain • Including scripting Vibrant community fueling innovation Excellent networking support Linuxcon 2013 09/16/13 7

Networking support includes the expected and more: Linuxcon 2013 09/16/13 8

In other words: GNU/Linux is a great fit as the OS for not just servers but even routers and switches in the modern data center Linuxcon 2013 09/16/13 9

So What ? What advantages does this provide ? Linuxcon 2013 09/16/13 10

What Linux as the network OS enables: Open routing and switching platform Unified management tool chain New ways of solving problems Neatly sidesteps a bunch of problems A potential to return IP networking to its roots: “rough consensus, working code” Linuxcon 2013 09/16/13 11

Open Routing/Switching implies a more participatory role for everyone to develop networking, transparency for troubleshooting and understanding Linuxcon 2013 09/16/13 12

Open Routing/Switching Platform Routing Suites Quagga Bridging Kernel STP, mstpd Discovery lldpd, open-lldp Net-snmp, collectd, Monitoring ganglia Linuxcon 2013 09/16/13 13

Tools to manage servers such as Chef, Puppet, Ansible etc. can also be used to manage the network Datacenter 1 Datacenter 1 09/16/13 14

New ways of solving the problem netplug, ifplugd Flexlink Keepalived or a script HSRP/VRRP to configure virtual MAC on bridge Linuxcon 2013 09/16/13 15

With Linux as the network OS, we neatly sidestep issues that arise from the traditional router OS' being a black box: Technologies such as netconf APIs for programming network Linuxcon 2013 09/16/13 16

What's missing ? Hardware acceleration of the networking forwarding path Linuxcon 2013 09/16/13 17

One Way Of Hardware Accelerating Routing Customer Routing Customer switchd switchd Protocols Applications Protocols Applications Routing ARP Ethernet Switch Routing ARP Ethernet Switch Linux Kernel Linux Kernel Table Table Interfaces Driver Table Table Interfaces Driver Switch Switch CPU, RAM, Flash, etc CPU, RAM, Flash, etc Silicon Silicon Switch ports show up as virtual interfaces (swp0, swp1 …) • typical tools - ifconfig, route, arp, ip, brctl, ethtool, tcpdump, etc Kernel FIB/ARP table are synchronized with HW • userspace can send/receive packets and insert routes normally Advanced operations use specialized APIs • expose hardware acceleration beyond stock Linux routing/bridging 09/16/13 18

Evolving Linux further: Consistent way to map data structures to hardware • Netlink's publish functionality not available with netfilter, for eg. Provide mechanisms to allow commands to fail if backend hardware install fails Linuxcon 2013 09/16/13 19

Evolution Of Network OS Linux-based Third Party Monolithic OS Linux OS OS Real-time OS Linux as the Linux as Embedded OS with No real OS, embedded OS: Network OS: while loop process and process and Native routing memory mgmt memory mgmt and switching Proprietary routing Proprietary routing Proprietary routing And switching stack And switching stack And switching stack Eg: ION Cumulus Eg: IOS, CatOS Eg: NX-OS, EOS Linux Linuxcon 2013 09/16/13 20

It's taken me all my life to learn what not to play. - Dizzy Gillespie 09/16/13 21

Imagine a world where every router ran GNU/Linux Linuxcon 2013 09/16/13 22

Thank You For Listening! ddutt@cumulusnetworks.com Linuxcon 2013 09/16/13 23