Networks - www.m00nie.com

Networks

A collection of 8 posts

Show "free" (not used for a while) ports on Cisco switch with one command

Show "free" (not used for a while) ports on Cisco switch with one command

Reasonably common task I come accross is to find free ports on switches (ports that havent been used for sometime). Sometimes its very easy where you can use an NMS or similar to give you a pretty output to show ports and their last input/output. However in my experience

Display the specific port used in an etherchannel for given src/dst info

Display the specific port used in an etherchannel for given src/dst info

Etherchannel on Cisco switches uses a hashing algorithm to determine which interface within the bundle to send the data over i.e. The port choice is deterministic and will always be the same unless ports are added to the bundle or the hashing algorithm is changed. It also means that

Quickest way to change an IP in windows

Quite often at work we need to manually change the IP of our laptops for testing various things. Since our laptops are not the quickest around town I quickly got bored of clicking on 5 different windows just to change IP. The I found the quite useful netsh command. netsh

Cacti host template for Cisco 1801 ISR

Cacti host template for Cisco 1801 ISR

Everyone loves Cacti (?) so heres the first of my own host templates for Cacti. I should just mention that although I I use these templates you should consider them as untested/use at your own risk etc. This one was made on a Cisco 1801 running 15.0.1M2(ED)

How to install and use snmpwalk

How to install and use snmpwalk

Snmpwalk is a great tool for Linux boxes. You can easily list all OIDs a SNMP host has to offer then filter the results to your needs and find OIDs to import into tools like Cacti. Snmpwalk is in most linux repos so its easy to install e.g: Fedora/

BGP Attributes

When BGP sends an UPDATE packet to a peer it sends path attributes associated with the prefix. These path attributes are then used by BGP to pick the best route to a destination. BGP attributes are similar to metrics in OSPF and EIGRP in the way it uses them to

QoS fields

The QoS fields used by the network device depend on the capabilities of the device and the QoS deployments of the network. Below is a little info about a few of these fields. This post will be edited over time with more info added. A table showing some of the

IP Precedence DSCP and CoS relationships

IP Precedence DSCP and CoS relationships

As part of studying the 642-642 QoS exam course is seems quite important to understand the relationship between the various ways of marking traffic. Below are some notes I've made so far about these relationships. This is note a post about the inner working of the various PHBs or their