Como configurar dois Servidores Proxies, para trocarem informações entre si.
Primeiro devemos instalar o pacote squid3 nos dois Servidores (Debian e derivados):
#apt-get update
#apt-get install squid3
O arquivo principal de configuração do squid3 encontra-se em:
/etc/squid3/squid.conf
squid.conf básico:
http_port 3128
refresh_pattern ^ftp: 1440 20% 10080
refresh_pattern ^gopher: 1440 0% 1440
refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
refresh_pattern . 0 20% 4320
acl manager url_regex -i ^cache_object:// +i ^https?://[^/]+/squid-internal-mgr/
acl localhost src 127.0.0.1/32 ::1
acl to_localhost dst 127.0.0.0/8 0.0.0.0/32 ::1
acl localnet src 10.0.0.0/8 # RFC 1918 possible internal network
acl localnet src 172.16.0.0/12 # RFC 1918 possible internal network
acl localnet src 192.168.0.0/16 # RFC 1918 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 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
http_access allow manager localhost
http_access deny manager
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports
http_access allow localhost
http_access allow localnet
http_access deny all
Para limpar o arquivo squid.conf
#echo "" > /etc/squid3/squid.conf
Arquivo squid.conf do Servidor Proxy I:
http_port 3128
icp_port 3130
refresh_pattern ^ftp: 1440 20% 10080
refresh_pattern ^gopher: 1440 0% 1440
refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
refresh_pattern . 0 20% 4320
acl manager url_regex -i ^cache_object:// +i ^https?://[^/]+/squid-internal-mgr/
acl localhost src 127.0.0.1/32 ::1
acl to_localhost dst 127.0.0.0/8 0.0.0.0/32 ::1
acl localnet src 10.0.0.0/8 # RFC 1918 possible internal network
acl localnet src 172.16.0.0/12 # RFC 1918 possible internal network
acl localnet src 192.168.0.0/16 # RFC 1918 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 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
cache_peer 192.168.1.254 sibling 3128 3130 proxy-only no-delay
log_icp_queries off
http_access allow manager localhost
http_access deny manager
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports
http_access allow localhost
http_access allow localnet
http_access deny all
Arquivo squid.conf do Servidor proxy II:
http_port 3128
icp_port 3130
refresh_pattern ^ftp: 1440 20% 10080
refresh_pattern ^gopher: 1440 0% 1440
refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
refresh_pattern . 0 20% 4320
acl manager url_regex -i ^cache_object:// +i ^https?://[^/]+/squid-internal-mgr/
acl localhost src 127.0.0.1/32 ::1
acl to_localhost dst 127.0.0.0/8 0.0.0.0/32 ::1
acl localnet src 10.0.0.0/8 # RFC 1918 possible internal network
acl localnet src 172.16.0.0/12 # RFC 1918 possible internal network
acl localnet src 192.168.0.0/16 # RFC 1918 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 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
cache_peer 192.168.1.1 sibling 3128 3130 proxy-only no-delay
log_icp_queries off
http_access allow manager localhost
http_access deny manager
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports
http_access allow localhost
http_access allow localnet
http_access deny all
Complete o arquivo squid.conf conforme suas necessidades.
Regras para o iptables:
Para redirecionar todo o trafego da rede para a porta do proxy:
iptables -t nat -A PREROUTING -i $LAN -p tcp -m iprange \
--src-range 192.168.1.10-192.168.1.253 -m state --stateNEW \
--dport 80 -j REDIRECT --to-port 3128
Para liberar a porta udp somente para rede interna:
iptables -I INPUT 1 -i $WAN -p udp -m udp --dport 3130 -j DROP
iptables -I INPUT 2 -i $LAN -p udp -m udp --dport 3130 -j ACCEPT
Para configurar os computadores que passarão pelo Servidor Proxy I:
Para configurar os micros que acessam via Servidor Proxy II:
