Proxy squid en Ubuntu

primero vamos a ejecutar este comando:

sudo iptables -L 

y si se muestran un monton de lineas, tenemos que ejecutar este comando:

sudo apt purge ufw 

Y reiniciamos el ordenador, cuando le encendamos volvemos a ejecutar el comando:

sudo iptables -L 

Y nos tiene que mostrar esto:

 Actualizar el sistema operativo:

sudo apt update
sudo apt upgrade

Instalar proxy-caché:

sudo apt install squid

Proteger copia de seguridad del fichero de configuración :

sudo cp /etc/squid/squid.conf /etc/squid/squid.conf.original
sudo chmod a-w /etc/squid/squid.conf.original

Editar fichero de configuración: 

sudo gedit /etc/squid/squid.conf  

ahora Copiamos y pegamos este contenido que tenemos que poner en el fichero:

#	WELCOME TO SQUID 3.5.27
#	----------------------------
#	
#	This is the documentation for the Squid configuration file.
#	This documentation can also be found online at:
#		http://www.squid-cache.org/Doc/config/
#	
#	You may wish to look at the Squid home page and wiki for the
#	FAQ and other documentation:
#		http://www.squid-cache.org/
#		http://wiki.squid-cache.org/SquidFaq
#		http://wiki.squid-cache.org/ConfigExamples
#

#Default:
# ACLs all, manager, localhost, and to_localhost are predefined.
#
#
# Recommended minimum configuration:
#

# Example rule allowing access from your local networks.
# Adapt to list your (internal) IP networks from where browsing
# should be allowed
#acl localnet src 10.0.0.0/8	# RFC1918 possible internal network
#acl localnet src 172.16.0.0/12	# RFC1918 possible internal network
#acl localnet src 192.168.0.0/16	# RFC1918 possible internal network
#acl localnet src fc00::/7       # RFC 4193 local private network range
#acl localnet src fe80::/10      # RFC 4291 link-local (directly plugged) machines

acl ai1 src 192.168.32.0/24

acl SSL_ports port 443
acl Safe_ports port 80		# http
acl Safe_ports port 21		# ftp
acl Safe_ports port 443		# https
acl Safe_ports port 70		# gopher
acl Safe_ports port 210		# wais
acl Safe_ports port 1025-65535	# unregistered ports
acl Safe_ports port 280		# http-mgmt
acl Safe_ports port 488		# gss-http
acl Safe_ports port 591		# filemaker
acl Safe_ports port 777		# multiling http
acl CONNECT method CONNECT

#Default:
# Deny, unless rules exist in squid.conf.
#

#
# Recommended minimum Access Permission configuration:
#
# Deny requests to certain unsafe ports
http_access deny !Safe_ports

# Deny CONNECT to other than secure SSL ports
http_access deny CONNECT !SSL_ports

# Only allow cachemgr access from localhost
http_access allow localhost manager
http_access deny manager

# We strongly recommend the following be uncommented to protect innocent
# web applications running on the proxy server who think the only
# one who can access services on "localhost" is a local user
#http_access deny to_localhost

#
# INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS
#

# Example rule allowing access from your local networks.
# Adapt localnet in the ACL section to list your (internal) IP networks
# from where browsing should be allowed
#http_access allow localnet
http_access allow localhost
http_access allow ai1

# And finally deny all other access to this proxy
http_access deny all

# Squid normally listens to port 3128
http_port 3128

Y ahora le damos a control+f(para buscar dentro del fichero)y ponemos "acl s" y tenemos que llegar hasta aquí:

como podemos ver en la imagen lo que hacemos es incluir en la linea 1197: acl ai1 src 192.168.32.0/24

 Ahora volvemos a buscar en el fichero la siguiente fila: 

http_access allow ai1

eso es lo que tenemos que añadir 

 Ahora tenemos que ponerlo en marcha poniendo los siguientes comandos:

sudo service squid restart

El de restart tarda unos segundos

 sudo service squid start

sudo service squid status 

 Para comprobar si nuestro servidor proxy funciona correctamente, solo tenemos que irnos a otro equipo y entrar a la configuración de red y eliminar la puerta de enlace. Luego entrar en el navegador Firefox e irnos a la configuración y dentro de ahí nos vamos a la configuración de red, donde tendemos que poner la IP de nuestro servidor "192.168.32.115" en el apartado de "Proxy HTTP y Proxy HTTPS" y ya podríamos navegar como cliente de un servidor proxy.

REPUESTO POR SI EL OTRO NO FUNCIONA:

# WELCOME TO SQUID 3.5.27

# ----------------------------

#

# This is the documentation for the Squid configuration file.

# This documentation can also be found online at:

# http://www.squid-cache.org/Doc/config/

#

# You may wish to look at the Squid home page and wiki for the

# FAQ and other documentation:

# http://www.squid-cache.org/

# http://wiki.squid-cache.org/SquidFaq

# http://wiki.squid-cache.org/ConfigExamples

#

#Default:

# ACLs all, manager, localhost, and to_localhost are predefined.

#

#

# Recommended minimum configuration:

#

# Example rule allowing access from your local networks.

# Adapt to list your (internal) IP networks from where browsing

# should be allowed

#acl localnet src 10.0.0.0/8 # RFC1918 possible internal network

#acl localnet src 172.16.0.0/12 # RFC1918 possible internal network

#acl localnet src 192.168.0.0/24 # RFC1918 possible internal network

#acl localnet src fc00::/7       # RFC 4193 local private network range

#acl localnet src fe80::/10      # RFC 4291 link-local (directly plugged) machines

acl ai1 src 192.168.32.0/24

acl SSL_ports port 443

acl Safe_ports port 80 # http

acl Safe_ports port 21 # ftp

acl Safe_ports port 443 # https

acl Safe_ports port 70 # gopher

acl Safe_ports port 210 # wais

acl Safe_ports port 1025-65535 # unregistered ports

acl Safe_ports port 280 # http-mgmt

acl Safe_ports port 488 # gss-http

acl Safe_ports port 591 # filemaker

acl Safe_ports port 777 # multiling http

acl CONNECT method CONNECT

#Default:

# Deny, unless rules exist in squid.conf.

#

#

# Recommended minimum Access Permission configuration:

#

# Deny requests to certain unsafe ports

http_access deny !Safe_ports

# Deny CONNECT to other than secure SSL ports

http_access deny CONNECT !SSL_ports

# Only allow cachemgr access from localhost

http_access allow localhost manager

http_access deny manager

# We strongly recommend the following be uncommented to protect innocent

# web applications running on the proxy server who think the only

# one who can access services on "localhost" is a local user

#http_access deny to_localhost

#

# INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS

#

# Example rule allowing access from your local networks.

# Adapt localnet in the ACL section to list your (internal) IP networks

# from where browsing should be allowed

#http_access allow localnet

http_access allow localhost

http_access allow ai1

# And finally deny all other access to this proxy

http_access deny all

# Squid normally listens to port 3128

http_port 3128