irom's Blog

Archive for the ‘Network’ Category

I’m using mini-PC Brix from Gigabyte in my home lab since middle of 2014. It’s size of palm hand. I’m using it with SSD 250GB disk and 16GB memory. I started with vSphere 5.1 installed but recently reinstalled to Ubuntu 14.04. I found out that VMware is more ‘resources demanding’, specially new versions 5.5 and 6. I also experienced  difficulty to obtain all evals I wanted to play with. Not to mention that it was almost impossible to use my USB 1TB disk other than assigned to on of the VMs.


On Ubuntu I am using KVM and VirtualBox for virtualization and can do pretty much the same as I did on vSphere. Plus  connecting and sharing external USB disk is very straightforward. The only disadvantage is that I do everything with command line. Recently I learned that I can do even better with free Proxmox VE. It’s based on KVM and gives very intuitive web gui.

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Last year I’ve seen news about IOU – Cisco IOS running on Unix. I was using GNS3 in the past, had not time to try IOU until last weekend. I’ve created Amazon EC2 Ubuntu instance with half of GB memory and run 3 routers connected with LAN interface. It worked great, see below

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Just purchased (almost 60 usd) two Netgear XE104 powerline ethernet adapters to connect old PC from basement to my internet switch upstairs. Very easy to install

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One major issue with Ethernet connectivity is proper configuration of speed and duplex. What will be the result of connecting ethernet auto-negotiate port of deivice 1 to 100/full ethernet port of device 2 ? See the answer on page 18 of Avaya VoIP guide

Scenario: R0 is connected to R1, R2 and R3 through DS3 (or OC3). Additionally R1, R2 And R3 are connected by Metro-Ethernet (simulated by SW1). All interfaces are in EIGRP 1. In case DS3 R0-R1 is broken traffic from R0 (source to R1 (destination should be shared between remaining two DS3s:

1) 1:1, traffic equally distributed between R0-R2 and R0-R3

2) 1:2, twice as much traffic on R0-R2 as on R0-R3

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It’s considerably easy to inject HSRP (Hot Standby Routing Protocol) packet into cisco unsecured network. There is interesting article by Stretch about HSRP Hijacking. He used python based scapy to do the job.  In fact windows shell and notepad are all is needed.  Just go to Start->Accessories->Run->type Powershell. In Powershell windows :

>notepad udpclient.ps1

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I’ve purchased SheevaPlug this summer. It’s a tiny Ubuntu server with 1.2GHz cpu and 512MB of RAM (ARM processor). It looks like a little wall plug and costs about 100usd. It’s easy to install  either a SD(HC) card or a USB stick to have not-volatile memory. I’m planning to use as my home proxy and log server. I’ve seen in the news that there is a next plugComputer  available on the market called GuruPlug (SheevaPlug2?)  And that one has Wi-Fi 802.11b/g, wow !

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