Sunday, September 26, 2021

Solved: VBoxGuestAdditions.iso (VERR_PDM_MEDIA_LOCKED)Solved:

   When inserting Guest Additions CD Image in a Debian VM you are getting VERR_PDM_MEDIA_LOCKED 

   There are many solutions, like: 
1) Executing 
  sudo apt-get upgrade 
  sudo apt-get install virtualbox-guest-additions-iso
2) Removing and inserting the cd from the VM configuration

and a third one which is the one that worked with me:

a) Start the VM
b) Open a terminal
c) Execute this:
  sudo su
  cd /media
  mkdir cdrom
  mount /dev/cdrom /media/cdrom
  cd cdrom

Hope this helps.


Saturday, July 24, 2021

Solved: GNS3 - Private Vlan - non-operational - Cisco


  In summary: private vlan are not working in GNS3, not even using IOU or VIRL


  User IOU i86bi-linux-l2-adventerprisek9-15.2d.bin


IOU3#show vlan private-vlan 

Primary Secondary Type              Ports

------- --------- ----------------- ------------------------------------------

500     501       community         Et0/1, Et0/2, Et1/0

500     502       isolated          Et0/0, Et0/3, Et1/0

Good luck!,

Wednesday, June 30, 2021

Super easy script - Python3 & optimizing every table of a mysql db


#The objetive of this script is to find all tables in a MYSQL DB and opmitize all of them

import dbconnect

import time

from datetime import datetime


startTime =

conn = dbconnect.dbconnect()


cur = conn.cursor()

print ("Starting time: ", startTime)

SQLQUERY=("SHOW TABLES") #Find every table in the DB


tables = cur.fetchall()

if len(tables)>0: #Prevent there are not tables in the list

  for table in tables:  #For every table in the DB


      SQLQUERY="OPTIMIZE TABLE "+ table[0]  #Construct the SQL QUERY

      print ("   Optimizing", table[0])




print ("Script execution time:",

print ("Ending time: ",

print ("******** ****** ")

Friday, June 25, 2021

IPv6 Deployment - LACNIC region

The video below shows the IPv6 deployment for the LACNIC region using a Bar Chart Race format

Made with

Tuesday, June 1, 2021

Solved: Finder on MAC does not find any files in its searches


   Finder can't find files when searching.


   I know there are many solutions, many with spotlight in system preferences, but the one that worked for me was to open a terminal window and run/execute:

  #sudo mdutil -E /

    I hope this is useful

Wednesday, May 19, 2021

Solved: nping - libnsock mksock_bind_addr(): Bind to 2001:db8:1::1:0 failed (IOD #1): Cannot assign requested address (99)


  When using nping (which comes with nmap) we receive the message:

libnsock mksock_bind_addr(): Bind to 2001:db8:1::1:0 failed (IOD #1): Cannot assign requested address (99)

Current situation:
  The issue is that nping can not bind to the IP 2001:db8:1::1

  There could be many different solutions, I'm only going to mention one.  What I did was to create a logical interface (tunnel type) with the IPv6 address I was needing (2001:db8:1::1). Here you have the commands.

ip tuntap add mode tun dev tun1
ip -6 addr add 2001:db8:1::1 dev tun1
ifconfig tun1 up

Finally, you could execute something like:

nping -6 -S 2001:db8:1::1 --tcp-connect -c 2 -p 53 <ipv6_dest> --source-mac 00:50:XX:XX:XX:35  --dest-mac 2c:XX:XX:XX:44:20

Hope this is useful