Category Archives: CCNP

PDF tools on Ubuntu

Ubuntu is my preferred operating system. I even use this OS on my work computer. This choice has some minor down sides. Most business software is developed for windows environments. But fortunately most commercial software on windows has an opensource … Continue reading

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European situation – Special military operation

My father was born in 1935. He lived his childhood in Rotterdam. As a 5 year old he expirienced firsthand the invasion of German troops of his beloved city. The expirience of the entire war that followed, hunted him for … Continue reading

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Laptop battery status

Recently the battery of my laptop is play up. It is constantly hungry for a powercord. And this is not the reason why I am using a laptop. The battery health was rapidly declining. So I installed a new laptop … Continue reading

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lstty

I found this little script on internet to get a list of all the usb connected devices. Unfortunaltly this script provides too much information for what I need it to do. Original script can be found on : https://unix.stackexchange.com/questions/144029/command-to-determine-ports-of-a-device-like-dev-ttyusb0 Pay … Continue reading

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Bash: IF shorthand

We all know how to make an if then else decision in programming or scripting languages. In bash , and most other languages it is possible to reduce several lines of code to a one-liners. Lets call that short-hand. A … Continue reading

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First Hop Redundancy Protocol – HSRP

Cisco proprietary HSRP protocol is a protocol for enabling a first hop fault tolerant router. Enabling your default gateway ip address to ‘live’ on more than one router. Back in the old days you had one router to exit a … Continue reading

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Access-list mask or wildcard

G’day all, today I was messing around with access-list.  And after getting my head around the weird subnets of rfc1918. Weird as in an A-class (/8) is reserved in A-space, B-class (/16) in reserved in C-space, and for the B-space … Continue reading

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Policy Based Routing

Policy-Based routing is a neat trick to tweak traffic streams. For Policy Based Routing to work you will the following; – Define traffic stream in an access-list. – Write down a policy. – Determine the inbound interface. First use an … Continue reading

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Error-Disable

When a network port encounters an error. This port is automatically shutdown to ensure network stability. When error-disable is enabled. The predefined error are as follows; arp-inspection bpduguard channel-misconfig dhcp-rate-limit              gbic-invalid                 l2ptguard                   link-flap mac-limit link-monitor-failure loopback oam-remote-failure pagp-flap port-mode-failure psecure-violation … Continue reading

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SSH error on cisco router

Enabling SSH on a Cisco router is not enough to guarantee SSH is working. Enabling ssh version 2.0 on a routers is as straight forward as;. >ip ssh version 1-2 I surely recommend the use of version 2, because ssh … Continue reading

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