A服务器可以上网，B服务器不行，想让B服务器借助A上网。
一、A服务器配置
1.安装squid
# yum install squid.x86_64
2.配置squid
# # 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 #定义 来源 10.0.0.0/8 这个网段的名称为 loaclnet 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 SSL_ports port 443 # 定义 443 端口的名称为 SSL_ports 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 # filemakeracl Safe_ports port 777 # multiling httpacl CONNECT method CONNECT
#
# Recommended minimum Access Permission configuration: 推荐的最小权限配置
#
# Deny requests to certain unsafe ports 不是Safe_ports组中的端口 全部禁止访问
http_access deny !Safe_ports
# Deny CONNECT to other than secure SSL ports 不是SSL_ports 组中端口的 禁止连接
http_access deny CONNECT !SSL_ports
# Only allow cachemgr access from localhost 允许这两个组 localhost manager 访问
http_access allow localhost manager
http_access deny manager 不允许 manager 组 访问
# 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
#
在这里添加你的规则，允许哪些客户端使用代理 如下
acl localhost src 10.11.0.31
# 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
# And finally deny all other access to this proxy 最后拒绝所有其它的请求
http_access deny all
# Squid normally listens to port 3128 服务监听端口
http_port 3128
# Uncomment and adjust the following to add a disk cache directory. 取消注释 并调整以下内容 以添加磁盘缓存目录。
#cache_dir ufs /var/spool/squid 100 16 256
# Leave coredumps in the first cache dir
coredump_dir /var/spool/squid
#
# Add any of your own refresh_pattern entries above these. 添加您自己的refresh_pattern条目
#
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
二、B服务器设置
临时修改环境变量，重启失效
#export PROXY=http://A服务器ip:80/
export http_proxy="http://210.45.72.XX:808"
永久生效
#vi /etc/profile 增加以下内容 ftp_proxy=A的ip:3128 http_proxy=A的ip:3128 https_proxy=A的ip:3128 no_proxy=www.baidu.com #百度不走代理 export ftp_proxy export http_proxy export https_proxy export no_proxy #source /etc/profile 生效
原文地址：https://www.cnblogs.com/centos2017/p/8969024.html