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Layer 2 Best Practices

I think I should be stepping up my security practices. Here’s an article that I came across summarized all the things one should know about Layer 2 security practices on Cisco switches.

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How to configure VLANs in Linux

This link from the Redhat knowledge base talks all about it. Here’s the list of steps and pointers I had to go through. 1. Make sure that the 8021q module is loaded modprobe 8021q 2. This step is important as…

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How to do a HTTP POST with Curl

This page proves there are people out there who forget about the same things I forget. Here’s the POST I wanted to run today. curl -d “platform=CHANNEL&processor_target=CERT&charge_type=PING”

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Cisco ASA/PIX Bandwidth limiting

Today, I got a chance to setup some bandwidth limiting on our Cisco ASA Firewall. The goal was to choke the speed of traffic going to our backup server to 250Mb/s. As our backup traffic goes through a firewall here’s…

How to allow ICMP through your Cisco ASA/PIX firewall

ICMP packets are not stateful, how does the ASA handle them by default? Internet Control Message Protocol (ICMP) pings and traceroute on the PIX Firewall are handled differently based on the version of PIX and ASA code. Inbound ICMP through…

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Most useful commands used in TOP

Top is amongst the most comprehensive and informative process display command in Linux. There’s no reason for a seasoned Linux sysadmin like myself not to know it! Top can display all the information you need to know about processes and…