Open source is not about cheaper tools or easier to use tools. Open source makes projects possible which might be impossible with propriety tools.
LinkedIn found out that commercial switching equipment manufacturers did not provide what they needed. They found that:
- Bugs in software that could not be addressed in a timely manner
- Software features on switches that were not needed in our data center environment. Exacerbating the problem was that we also had to deal with any bugs related to those features.
- Lack of Linux based platform for automation tools, e.g. Chef/Puppet/CFEngine
- Out-of-date monitoring and logging software, i.e. less reliance on SNMP
- High cost of scaling the software license and support.
What they wanted was:
- Run our merchant silicon of choice on any hardware platform
- Run some of the same infrastructure software and tools we use on our application servers on the switching platform, for example, telemetry, alerting, Kafka, logging, and security
- Respond quickly to requirements and change
- Advance DevOps operations such that switches are run like servers and share a single automation and operational platform
- Limitless programmability options
- Feature velocity
- Faster, better innovation cycle
- Greater control of hardware and software costs
This could not be provided by any propriety vendor.
So they had to build their switches themself. This was only possible because they could reuse on freely available open source software. In the future they might even use FPGAs and program them with open source FPGA tools .