Our earth is very slowly slowing down, which means every now and then scientists call to add an extra second to our time to compensate. The last was in 2012, the next one is coming up on June 30, 2015 23:59:60 UTC. For more information about this leap second, check timeanddate.com.

Cisco posted an impact analysis on their website with links to bug reports which determine the impact. While most campus products are unaffected, there are some warnings on datacenter products where the leap second update can lead to a crash or lockup.

My intention is not to scare, … Read more


Cisco has released version 3.1 of its virtualised switch (available for download here). It comes with increased scalability and resiliency, but one very cool thing stood out for me: the Virtual Switch Update Manager or VSUM.

The VSUM is not the only cool improvement on the virtual switch, here’s an overview of changes:

  • Scale
    • Increased Scalability (Advanced Edition) – More than doubles the scale from the previous release. The virtual switch now supports 250 hosts/servers per switch with 10,000 ports per switch. In addition it supports 4094 active VLANs and 16 million VXLAN (6144 active VXLANs) per switch across
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