Peter Phaal

Author Archives: Peter Phaal

Cumulus Networks, sFlow and data center automation

 Cumulus Networks and InMon Corp have ported the open source Host sFlow agent to the upcoming Cumulus Linux 2.1 release. The Host sFlow agent already supports Linux, Windows, FreeBSD, Solaris, and AIX operating systems and KVM, Xen, XCP, XenServer, and Hyper-V hypervisors, delivering a standard set of performance metrics from switches, servers, hypervisors, virtual switches, and virtual machines – see Visibility and the software defined data center.

The Cumulus Linux platform makes it possible to run the same open source agent on switches, servers, and hypervisors – providing unified end-to-end visibility across the data center. The open networking model that Cumulus is pioneering offers exciting opportunities. Cumulus Linux allows popular open source server orchestration tools to also manage the network, and the combination of real-time, data center wide analytics with orchestration make it possible to create self-optimizing data centers.

Install and configure Host sFlow agent

The following command installs the Host sFlow agent on a Cumulus Linux switch:

sudo apt-get install hsflowd

Note: Network managers may find this command odd since it is usually not possible to install third party software on switch hardware. However, what is even more radical is that Cumulus Linux allows users to download source Continue reading

Guest Blog: REST API for Cumulus Linux ACLs

Cumulus Linux: REST API for Cumulus Linux ACLs

RESTful control of Cumulus Linux ACLs included a proof of concept script that demonstrated how to remotely control iptables entries in Cumulus Linux.  Cumulus Linux in turn converts the standard Linux iptables rules into the hardware ACLs implemented by merchant silicon switch ASICs to deliver line rate filtering.

Previous blog posts demonstrated how remote control of Cumulus Linux ACLs can be used for DDoS mitigationand Large “Elephant” flow marking.

A more advanced version of the script is now available on GitHub

The new script adds the following features:

  1. It now runs as a daemon.
  2. Exceptions generated by cl-acltool are caught and handled
  3. Rules are compiled asynchronously, reducing response time of REST calls
  4. Updates are batched, supporting hundreds of operations per second

The script doesn’t provide any security, which may be acceptable if access to the REST API is limited to the management port, but is generally unacceptable for production deployments.

Fortunately, Cumulus Linux is a open Linux distribution that allows additional software components to be installed. Rather than being forced to add authentication and encryption to the script, it is possible to install additional software and leverage the capabilities of a mature web server such as Apache. The Continue reading