Monthly Archives: July 2011

Possible Reasons for LAN Traffic Congestion

Posted on July 30, 2011 by Humair

If you are experiencing slowness on your LAN here are some possible reasons that you can investigate:

Posted in Networking | Tagged broadcast storms, failing router, failing switch, LAN slowness, LAN traffic congestion, low bandwidth, network issues, network loops, network slowness, networking, Reasons for LAN Traffic Congestion, slow, Traffic Congestion | Leave a comment

Useful FTOS “show” commands

Posted on July 20, 2011 by Humair

There are several FTOS “show” commands that can provide very useful information regarding Force10 Networks switches/routers. I have outlined a number of these very useful commands with a short description of each below. However, keep in mind that although most … Continue reading →

Posted in Force10 Networks, Networking | Tagged Force10, Force10 FTOS, Force10 Networks, Force10 show commands, Force10 switches, FTOS, show, show bootvar, show commands, show environment, show inventory, show linecard, show redundancy, show rpm, show sfm, show version, switches | Leave a comment

Use Perl’s regex to count the # of words in a file

Posted on July 17, 2011 by Humair

In the below code I use Perl’s regex capabilites to count the # of words in a file. Notice I used “\s” in the regex expression to account for not only spaces but also tab and new line characters. In … Continue reading →

Posted in Perl, Programming Languages | Tagged count words, file word count, file word counter, open file, perl, perl close file, perl code, perl file input, perl open file, perl read file, perl regex, perl regular expressions, perl word count code, regex, regex expression, regular expressions, whitespace, word counter | Leave a comment

Port Monitoring on Force10 Switches

Posted on July 15, 2011 by Humair

In this lab I will demonstrate how to do port monitoring on Force10 switches and capture the packets using a network protocol analyzer (Wireshark in this case). Port monitoring allows the copying of all incoming/outgoing packets on a specific port … Continue reading →

Posted in Force10 Networks, Labs, Networking | Tagged Force10, Force10 switch, Force10 switches, network protocol analyzer, packet analyzer, Packet Sniffer, Packet Sniffing, Port Mirroring, Port Monitoring, Sniffer, VRRP, wireshark | 1 Comment

Scalar and List Contexts in Perl

Posted on July 13, 2011 by Humair

One of the most important concepts to understand in Perl programming is that of evaluation based on context. In Perl, an operation such as an assignment or function call can give two different results based on the context of the … Continue reading →

Posted in Perl, Programming Languages | Tagged context, context based evaluation, evaluation, list, list context, localtime, perl, perl time function, scalar, scalar context, time, time function | Leave a comment

Setup VRRP with Force10 Switches

Posted on July 12, 2011 by Humair

In this lab I setup Force10 switches with Virtual Router Redundancy Protocol (VRRP). VRRP is a redundancy protocol used to eliminate a single point of failure between a gateway and its respective hosts within the same subnet. I use three … Continue reading →

Posted in Force10 Networks, Labs, Networking, Protocols | Tagged E1200, Force10, Force10 E1200, Force10 Networks, Force10 S55, Force10 S60, FTOS, gateway, gateway redundancy, redundancy protoco, S55, S60, virtual address, virtual IP, Virtual Router Redundancy Protocol, VRRP, VRRP group | 2 Comments

Unix shell script – convert Mac ASCII file to Unix ASCII file

Posted on July 10, 2011 by Humair

With some applications like Microsoft Word you can save a file in ASCII format. However, for new lines Macs use a carriage return (ASCII character 015) while Unix uses a linefeed (ASCII character 012). If you save the file as … Continue reading →

Posted in Linux, Operating Systems, Programming Languages, Shell Scripts | Tagged ASCII, carriage return, linefeed, MAC, Mac to Unix, Microsoft Windows, new line, shell script, Unix, windows | 1 Comment