Tech Notes: Ping Sweep an IP Subnet


This is my current goto code snippet for using the BASH command line to perform a ping sweep through an IPv4 subnet. for i in `seq 1 255`; do ping -c 1 192.168.1.$i | tr \\n ‘ ‘ | awk ‘/1 received/ {print $2}'; done This script is deliberately simple, only works for /24 subnets but […]

Thoughts of My Day: VCE Always Was An EMC Property


EMC announced during it’s quarterly results that it was taking a larger position in VCE. VCE was always an EMC asset, co-operation with partners Cisco, Intel and VMware has never been strong and this simply closes out the current chapter.  The end result positions EMC to also be a “IBM style” company with a full […]

Confusing Times in Networking and Cognition Jumps


I’ve been researching four different and distinct types of networking in the last few weeks. I’m finding that the cognition required to jump between technologies is making my head hurt. Here is a summary of four technology areas that interest me this week. Optical Networking As part of research project I have been getting deep […]

Response: http2 explained


Been researching HTTP2 protocol on the basis that is will, more or less, be the dominant protocol on the Internet and everywhere else. Aside from the sense of excitement I get from looking at solving old problems, HTTP2 is a huge change for networking and this site has the best explanation I’ve found so far. Check […]

IOS: show tcp vty

On Cisco IOS, this is a very useful command “show tcp vty xx” to show TCP statistics of the VTY session. If you think your terminal is running slow because of packet loss or delay then this command will provide visibility. The other cause is the CPU/Memory running slow if you don’t see any errors on the TCP (as you can see below).

Killer Apps in the Gigabit Age | Pew Research Center’s Internet & American Life Project


Very, very funny quote in the Pew Research Report: How could people benefit from a gigabit network? One expert in this study, David Weinberger, a senior researcher at Harvard’s Berkman Center for Internet & Society, predicted, “There will be full, always-on, 360-degree environmental awareness, a semantic overlay on the real world, and full-presence massive open […]