proxy autenticado

boa tarde.
editei um conf simples do proxy squid3 para autenticar usuários da rede local.porém,quando aciono o navegador da máquina cliente não aparece nenhum pronpt de autenticação para autenticar e nega tudo.se eu comentar as regras ele volta a a ficar funcional.mas eu queria aplicar as regras.
alguém pode me ajudar a solucionar esse problema?

mostre como esta seu arquivo de configuração.

http_port 3128
visible_hostaname proxy
#cache do squid
cache_mem 64 MB
maximum_object_size_in_memory 64 KB
maximum_object_size 512 MB
maximum_object_size 0 KB
cache_swap_low 90
cache_swap_high 95
cache_dir ufs /var/spool/squid3 2048 16 256
cache_access_log /var/log/squid3/access.log
refresh_pattern ^ftp: 15 20% 2280
refresh_pattern ^gopher: 15 0% 2280
refresh_pattern ^ftp: 15 20% 2280
########################################################
#regras das acls
acl manager proto cache_object
acl localhost src 127.0.0.1/32
acl SSL_ports port 443 563
acl Safe_ports port 80 #http
acl Safe_ports port 21 #ftp
acl Safe_ports port 80 #http
acl Safe_ports port 443 563 #http,snews
acl Safe_ports port 70 #gopher
acl Safe_ports port 210 #wais
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 Safe_ports port 901 #swat
acl Safe_ports port 1025-65535 #portas altas
acl purge method PURGE
acl CONNECT method CONNECT

http_access allow manager localhost
http_access deny manager
http_access allow purge localhost
http_access deny purge
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports
#rede local
acl redelocal src 192.168.10.0/24
acl redelocal src 192.168.20.0/24
http_access deny !redelocal

#regras de bloqueio
acl bloqueados url_regex -i "/etc/squid3/bloqueados"
http_access deny bloqueados

acl palavrasproibidas dstdom_regex "/etc/squid3/palavrasproibidas"
http_access deny palavrasproibidas

acl extban url_regex -i "/etc/squid3/extban"
http_acces deny extban

#regras de autenticação
auth_param basic realm Digite Usuário e Senha!
auth_param basic program /usr/lib/squid3/ncsa_auth /etc/squid3/passwd
acl autenticados proxy_auth REQUIRED
http_access allow autenticados

http_access allow localhost
http_access allow redelocal
http_access deny all

teste com essas regras, ajuste para sua rede (melhoria) .

################################################## AUTENTICACAO ###############################################
#PORTA
http_port 3128
#NOME DO SERVIDOR
visible_hostname Firewall



############### SITES QUE NAO PASSAM POR AUTENTICACAO #######################

acl sites_sem_autenticar_toda_rede url_regex "/etc/squid3/sites_sem_autenticar_toda_rede"
http_access allow sites_sem_autenticar_toda_rede


######################### PEDE A AUTENTICAÇO NO PROXY ##########################

auth_param basic realm "Entre com seu usuário e senha para nevegar"
auth_param basic program /usr/lib/squid3/basic_ncsa_auth /etc/squid3/passwd
auth_param basic children 5
auth_param basic credentialsttl 8 hours ###( tempo que o usuário ficara logado até pedir autenticação novamete )
auth_param basic casesensitive off ### ( Case sensitive on diferencia maiuscula e minusculas )
acl autenticados proxy_auth REQUIRED

#DEFINE IDIOMA DE MENSAGENS DE ERROS
error_directory /usr/share/squid3/errors/Portuguese

################################################### CONFIGURACAO DE CACHE E DIRETORIO ############################
#LIMITE CACHE HTTP
request_body_max_size 0 MB

#CAMINHO DE LOG DE ACESSO DO SQUID E CAMINHO DE CACHE
cache_dir ufs /var/log/squid3/cache 5000 16 256
access_log /var/log/squid3/access.log
cache_log /var/log/squid3/cache.log

#DEFINE QUANTIDADE DE MEMORIA QUE O SERVIDOR IRA UTILIZAR PARA CACHE
cache_mem 32 MB

#DEFINE O TAMANHO MAXIMO DO OBJETO ARMAZENADO NO DISCO RIGIDO
maximum_object_size_in_memory 128 KB
maximum_object_size 156 MB
minimum_object_size 0 KB

#descarte arquivos antigos
cache_swap_low 90
cache_swap_high 95

#TEMPO DE VIDA DOS OBJETOS NO CACHE
refresh_pattern ^ftp: 360 20% 10080
refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
refresh_pattern . 0 20% 4320

acl SSL_ports port 443 563 10000
acl Safe_ports port 80 81 200 210 280 407 432 443 488 563 588 777 901 1550 3256 3442 1024-65535 5222 8080 10000 39350
acl purge method PURGE
acl CONNECT method CONNECT

http_access deny manager
http_access deny purge
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports

####################################### LIBERACAO DE ATUALIZACAO DO ANTI-VIRUS######################################
acl liberacao_antivirus url_regex "/etc/squid3/liberacao_antivirus"
http_access allow liberacao_antivirus

####################################### CONTROLE DE ACESSO - LIBERADO E BLOQUEADO ###################################
######################################### DESCRICAO DO BLOQUEIO #####################################################
# Grupo 1 - usuario_acessototal - os usuários tem acesso livre a Internet
# Grupo 2 - usuario_acessorestrito - os usuários acessam qualquer site que não estiver na lista sites_bloqueados
# Grupo 3 - usuario_acessobloqueado - os usuários acessam somente os sites que estiverem na lista sites_permitidos

################################################# SITES LIBERADOS TODA REDE #########################################

acl sites_permitidos_toda_rede url_regex "/etc/squid3/sites_permitidos_toda_rede"
http_access allow sites_permitidos_toda_rede


################################################## usuario_acessototal ###############################################
# Grupo 1
# USUARIOS SEM RESTRICAO

acl usuario_acessototal proxy_auth "/etc/squid3/usuario_acessototal"
http_access allow usuario_acessototal

################################################### bloqueio de videos (PODE GERAR LENTIDAO NOS SITES ###############
#acl bloqueio_video_online rep_mime_type -i "/etc/squid3/bloqueio_video_online"
#http_reply_access deny bloqueio_video_online

################################################### downloads_bloqueados ###############################################
# Bloqueio por download de arquivo

acl downloads_bloqueados url_regex -i "/etc/squid3/downloads_bloqueados"
http_access deny downloads_bloqueados

#################################################### palavras_proibidas #################################################
# Bloqueio por palavras

acl palavras_proibidas url_regex -i "/etc/squid3/palavras_proibidas"
http_access deny palavras_proibidas

######################################## ACL UTILIZADA PARA BLOQUEIO DE SITES ############################################
# Bloqueio de sites por URL

acl sites_negados_usuario_acessorestrito url_regex -i "/etc/squid3/sites_negados_usuario_acessorestrito"
http_access deny sites_negados_usuario_acessorestrito

###################################################### usuario_acessorestrito #############################################
# Grupo 2

#*** Usuários com acesso controlado pelos sites bloqueados
acl usuario_acessorestrito proxy_auth "/etc/squid3/usuario_acessorestrito"
acl sites_negados_usuario_acessorestrito url_regex -i "/etc/squid3/sites_negados_usuario_acessorestrito"

http_access deny sites_negados_usuario_acessorestrito
http_access allow usuario_acessorestrito !sites_negados_usuario_acessorestrito

##################################################### usuario_acessobloqueado ##############################################
# Grupo 3

#*** Usuarios com acesso somente aos sites liberados
acl usuario_acessobloqueado proxy_auth "/etc/squid3/usuario_acessobloqueado"
acl sites_permitidos_usuario_acessobloqueado url_regex -i "/etc/squid/sites_permitidos_usuario_acessobloqueado"

http_access allow sites_permitidos_usuario_acessobloqueado
http_access deny usuario_acessobloqueado !sites_permitidos_usuario_acessobloqueado

#######################################################################################################
# liberação para autenticar --- cuidado pois se mover ele libera navegacao para Grupo 2

http_access allow autenticados
acl redelocal src 10.1.1.0/24
http_access allow redelocal
http_access deny all

bom dia.
amigo abrigado pela boa intenção,mas o seu conf não funfou.
se puder apenas me mostrar onde estou errarndo no meu conf do squid na primeira comfiguração passada desde já agradeço;
pois isso seria um aprendizado para as futuras configurações.e eu saberia onde errei para corrigir com conhecimento.
abrigado.