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Linux Sad Servers Uncategorized YouTube CCESTE

Sad Servers 07 – Lhasa : Easy Math

Type: Do

Access: Email

Description: There’s a file /home/admin/scores.txt with two columns (imagine the first number is a counter and the second one is a test score for example).

Find the average (more precisely; the arithmetic mean: sum of numbers divided by how many numbers are there) of the numbers in the second column (find the average score).

Use exaclty two digits to the right of the decimal point. i. e., use exaclty two “decimal digits” without any rounding. Eg: if average = 21.349 , the solution is 21.34. If average = 33.1 , the solution is 33.10.

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Linux Sad Servers Uncategorized YouTube CCESTE

Sad Servers 05 – Taipei : Come a-knocking

Level: Easy

Type: Hack

Description: There is a web server on port :80 protected with Port Knocking. Find the one “knock” needed (sending a SYN to a single port, not a sequence) so you can curl localhost.

Test: Executing curl localhost returns a message with md5sum fe474f8e1c29e9f412ed3b726369ab65. (Note: the resulting md5sum includes the new line terminator: echo $(curl localhost))

La versión del Pelado Nerd la encontrás acá https://www.youtube.com/watch?v=45E_RChOfz0

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Linux Sad Servers Uncategorized YouTube CCESTE

Sad Servers 04 – The Command Line Murders – Resuelto en el 2do intento

Level: Easy

Description: This is the Command Line Murders with a small twist as in the solution is different

Enter the name of the murderer in the file /home/admin/mysolution

Anteriormente intenté resolverlo sin éxito, te lo dejo acá para que lo veas
https://youtu.be/IM8A8nifWjg

Este es el segundo intento, ya con alguna idea de como encarar el desafío

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Linux Sad Servers Uncategorized YouTube CCESTE

Sad Servers 04 -😵 The Command Line Murders😵 Failed 😵

Level: Easy

Description: This is the Command Line Murders with a small twist as in the solution is different

Enter the name of the murderer in the file /home/admin/mysolution

Honestamente no sabía ni por donde arrancar, pero creo que nos quedaron algunos buenos indicios para un segundo intento

Recuerden que nadie nació sabiendo, lo importante es aprender en el camino 😊

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Linux Sad Servers Uncategorized YouTube CCESTE

Sad Servers 03 – Santiago : Find the secret combination

Level: Easy

Type: Do

Description: Alice the spy has hidden a secret number combination, find it using these instructions:

1) Find the number of lines with occurrences of the string Alice (case sensitive) in the *.txt files in the /home/admin directory
2) There’s a file where Alice appears exactly once. In that file, in the line after that “Alice” occurrence there’s a number.
Write both numbers consecutively as one (no new line or spaces) to the solution file.
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Linux Sad Servers Uncategorized YouTube CCESTE

Sad Servers 02 – Saskatoon : counting IPs

Level: Easy

Type: Do

Description: There’s a web server access log file at /home/admin/access.log. The file consists of one line per HTTP request, with the requester’s IP address at the beginning of each line.

Find what’s the IP address that has the most requests in this file (there’s no tie; the IP is unique). Write the solution into a file /home/admin/highestip.txt.

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Linux Sad Servers Uncategorized YouTube CCESTE

Sad Servers 01 – Saint John : What is writing to this log file?

Scenario: “Saint John”: what is writing to this log file?
Level: Easy
Type: Fix
Description: A developer created a testing program that is continuously writing to a log file /var/log/bad.log and filling up disk. You can check for example with tail -f /var/log/bad.log.
This program is no longer needed. Find it and terminate it.

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MPLS Networking Uncategorized

MPLS 06 – Configurando L2VPN VPLS Cisco to Juniper

Continuando con VPNs de capa 2, hoy conectaremos un VPLS desde Cisco a Juniper

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00:00 Intro y musiquita
00:34 Bienvenida
01:22 Repaso Laboratorio y conectividad MZA y CEs
04:25 Conectividad OSPF Juniper
06:44 Añadiendo P5 a VPLS – Extremo Cisco
08:24 Routing Instance VPLS en Junos
11:25 Verificando VPLS en Junos
12:68 Desacoplando VPLS en Junos
15:40 Stack de etiquetas en Junos
16:41 Examinando FEC en Wireshark
17:45 Acoplando interfaces CE al Routing Instance
19:48 Encapsulaciones en Junos
23:00 Testing Extremo a Extremo
24:09 Verificando VPLS up en Junos
25:10 Stack de etiquetas en Wireshark
26:04 Repaso rápido
26:34 Despedida
26:44 Outro y musiquita

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MPLS Networking Uncategorized

MPLS 04 – L2VPN, VPLS, Split Horizon, Full Mesh y H-VPLS

Continuando con VPNs de capa 2, introduciendo el concepto de VPLS, Split Horizon, Full Mesh y H-VPLS

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00:00 Intro y musiquita
00:34 Bienvenida
01:33 Repaso Laboratorio y conectividad MZA y CEs
02:15 Porqué falla la conectivdad entre sitios
03:37 Qué es VPLS
06:03 Qué es Split Horizon
07:00 En busca de las tramas perdidas
10:40 Verificando Split Horizon en el VFI
11:04 Flat VPLS vs H-VPLS
18:41 El largo camino al destino cercano
20:00 Tramas repetidas y no tanto
22:28 Confundiendo el stack de etiquetas MPLS
24:03 En resumen, VPLS
24:48 Despedida
25:05 Outro y musiquita

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MPLS Networking Uncategorized

MPLS 05 – Configurando L2VPN Cisco y MikroTik

Vistazo a VPNs de capa 2 y examinando conectividad con Wireshark
Hoy tenemos un nuevo P7 ejecutando MikroTik RouterOS v6

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00:00 Intro y musiquita
00:18 Bienvenida
01:03 Extendiendo el laboratorio
01:18 Repasando laboratorio P1
02:16 Clientes L2
02:40 L2VPN P1-P4
06:35 Encapsulación L2VPN P1-P4 en Wireshark
10:35 Accediendo a P7 via Winbox
12:27 Direccionamiento IP para P7
14:38 Loopbacks en RouterOS
15:28 OSPF en RouterOS
17:47 LDP en RouterOS
19:18 FEC en RouterOS
20:15 Traceroute en RouterOS – Leyendo etiquetas MPLS
21:50 Agregando neighbor P7 al VFI
22:04 VPLS en RouterOS
24:30 Examinando en Wireshark
26:17 FEC128 y qué es esto
28:06 Asignando VPLS a un Bridge
29:52 L2VPN P1-P7 y ping exitoso
30:30 Despedida
30:50 Outro y musiquita