Well-Known Intervals
Listed below are many events which occur on network devices at well-known intervals. The list is provided to serve as an aid while troubleshooting recurring network disruptions.
Troubleshooting
Cisco ASA Packet Captures for Fun and Profit
As many of you know my background isn’t in enterprise, but I currently fill that role in my $job.
Nexus 1000v – Out of Ports on a Virtual Switch?
Yesterday, work presented an interesting issue I wanted to share with everyone.
IOS Embedded Packet Capture
Tired of setting up SPAN sessions? Need to do some packet analysis? Since IOS 12.4(20)T Cisco has made Embedded Packet Capture (EPC) available.
Measuring Cable Lengths on a Catalyst Switch
A while back, I was playing on a 3750 switch in a customers lab and came across something I’ve never seen before. It seems that some Cisco switches have a built in Time-domain reflectometer, or TDR.
Netcat – secret weapon
Netcat or nc, is a forgotten tool in too many arsenals these days. It lays dormant waiting at the command line to make connections across the globe for you.
Mail Server Relay Testing
As you may know, I am not big in the server world, even less into mail servers. They make me sick.
Testing TCP Connectivity on Cisco Devices
Ever thought you might be having some Layer 4 connectivity issues? Pings as you should know are ICMP transmissions and ICMP is a Layer 3 protocol (commonly used to send error messages).
How does latency effect throughput?
One of the questions I get asked several times a week by my clients is as such.