Redirecionamento para porta proxy

Olá pessoal,

implementei um proxy com controle de banda para download em um servidor diferente do meu gateway, coloquei aquela rega do iptables redirecionando para outra maquina (iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j DNAT --to 190.158.70.2:3128). O problema ´q ele aceite certinho a regra no iptables mas na verdade ele nao esta direcionando nada, por exemplo: se eu desativar o squid na outra maquina continuo navegando. segue meu arquivo de configuração do squid...

desde ja agredeço as ajudas

squid.conf
http_port 3128
cache_mem 60 MB
maximum_object_size 4096 KB
minimum_object_size 0 KB
cache_dir ufs /var/cache/squid 100 16 256
cache_access_log /var/log/squid/access.log
cache_log /var/log/squid/cache.log
cache_store_log /var/log/squid/store.log
mime_table /etc/squid/mime.conf
client_netmask 255.255.255.255

#Default:
refresh_pattern ^ftp: 1440 20% 10080
refresh_pattern ^gopher: 1440 0% 1440
refresh_pattern . 0 20% 4320

#Defaults:
acl all src 0.0.0.0/0.0.0.0
acl manager proto cache_object
acl localhost src 127.0.0.1/255.255.255.255
acl SSL_ports port 443 563
acl Safe_ports port 80 21 443 563 70 210 1025-65535
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 configuration:
http_access allow manager localhost
http_access deny manager
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports
#############################################################

### REGRAS PARA USAR COM REDIRECIONAMENTO ###
httpd_accel_host virtual
httpd_accel_port 80
httpd_accel_with_proxy on
httpd_accel_uses_host_header on

##### CONTROLE DE BANDA PARA DOWNLOAD ######

# Redes
acl lan_pj url_regex -i 190.158.70
#_______________________________________________________________________________

# Arquivos Controlados
acl controle url_regex -i ftp .mov .mpeg .wav .tar .mp3 .exe .zip .rar .pps .pdf
# ______________________________________________________________________________

delay_pools 2
delay_class 1 2
delay_parameters 1 -1/-1 -1/-1

delay_access 1 allow lan_pj

delay_class 2 2
delay_parameters 2 13000/13000 13000/13000

delay_access 2 allow controle

############################################