小型企业的一般互联网宽带接入比较差的。公共上网带宽也不很充足的，再加上有一些下载或都视频流，对于web浏览将有严重的影响的。可能听过各种网络慢的声音。
在以上的基本目标下，准备使用squid做透明代理，这样在用户不用改变任何的配置情况下，将有一定的网络浏览速度的提升的。
基本系统：
Centos 6.7 内核：2.6.32.547
双网卡
iptables 1.4.7
squid 3.5.15
开始安装配置
yum install -y gcc make
软件存放路径：/usr/local/src/
安装路径：/usr/local/squid/
cd /usr/local/src/ wget tar -zxvf squid-3.5.15.tar.gz cd squid-3.5.15 ./configure --prefix=/usr/local/squid / --enable-arp-acl / --enable-ssl / --with-aufs-threads=64 / --enable-ltdl-convenience #参数说明请参考 ./configure --help make && make install 基本安装完成，未有错误。如遇到错误请自行找度妈与谷爸吧！
以上安装完成以后的，软件安装位置：/usr/local/squid 下，目录结构如下：
[root@nginx-master squid]# ll
total 24 drwxr-xr-x. 2 root root 4096 Feb 26 16:49 bin drwxr-xr-x. 2 root root 4096 Mar 29 15:25 etc #配置文件 drwxr-xr-x. 2 root root 4096 Feb 26 16:49 libexec drwxr-xr-x. 2 root root 4096 Feb 26 16:49 sbin #squid 执行程序 drwxr-xr-x. 5 root root 4096 Feb 26 16:49 share #文档相关 drwxrwxrwx. 5 squid squid 4096 Feb 26 16:49 var 目录cache与logs
编辑配置文件
cd /etc vim squid.conf # # Recommended minimum configuration: # #squid run user cache_effective_user squid # 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 192.168.8.0/24 # 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 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 acl game dstdomain games.sina.com.cn acl sport url_regex -i ccc.x.jd.com #------ 47jp acl jp src 192.168.47.188 acl jp src 192.168.47.187 acl jp src 192.168.47.32 acl jp src 192.168.47.153 acl jp src 192.168.47.148 acl jp src 192.168.47.147 acl jp src 192.168.47.105 acl jp src 192.168.47.130 acl jp src 192.168.47.230 acl jp src 192.168.47.103 acl jp src 192.168.47.150 acl jp src 192.168.47.127 acl jp src 192.168.47.123 acl jp src 192.168.47.158 #------- 4-5man acl man src 192.168.4.97 acl man src 192.168.4.99 acl man src 192.168.4.96 acl man src 192.168.4.101 acl man src 192.168.5.2 acl man src 192.168.5.3 acl man src 192.168.5.8 acl man src 192.168.5.20 acl man src 192.168.4.13 # # Recommended minimum Access Permission configuration: # # Deny requests to certain unsafe ports http_access deny !Safe_ports http_access deny game sport # Deny CONNECT to other than secure SSL ports http_access deny CONNECT !SSL_ports # Only allow cachemgr access from localhost http_access allow man 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 # And finally deny all other access to this proxy http_access deny all # Squid normally listens to port 3128 http_port 192.168.10.2:3128 transparent #默认配置为：http_port 3128 此时为代理模式 http_port 3129 #系统日志有报错：增加此参数 # Hostname visible_hostname ancc # 不加此参数时，系统启动时会有警告 # Uncomment and adjust the following to add a disk cache directory. #cache_dir ufs /usr/local/squid/var/cache/squid 100 16 256 cache_dir ufs /home/data/cache 4096 16 256 #修改存储目录以后，要给目录增加相应权限 cache_dir ufs /home/data/cache0 4096 16 256 cache_dir ufs /home/data/cache1 4096 16 256 cache_dir ufs /home/data/cache2 4096 16 256 access_log /home/data/log/access.log cache_store_log /home/data/log/store.log cache_log /home/data/log/cache.log cache_effective_user squid cache_effective_group squid # Leave coredumps in the first cache dir coredump_dir /home/data/cache #coredump_dir /usr/local/squid/var/cache/squid #manager mail cache_mgr [email protected] cache_mem 800 MB #20160322 #cache_swap_high 100% #cache_swap_low 80% maximum_object_size 1024 KB # # Add any of your own refresh_pattern entries above these. # 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
以上是我的用的配置文件，详细的配置参数可参考如下网址：http://zyan.cc/book/squid/index.html
上面的配置中：我修改了cache目录与log的存储位置的到/home/data目录下，因为是测试了所以没有详细的规划硬盘的使用空间。如果实施时，需要进一步的规划磁盘空间。
配置文件完成，保存退出
cd /usr/local/squid/sbin/ ./squid -z #初始化cache目录 ./squid #启动程序 ps -axu | grep squid #查看服务是否正常启动 netstat -nat | grep 3128 #查看端口是否被监听
此配置为透明代理，需要开启路由转发与iptables NAT和端口转发
开启转发（永久的方法）
vim /etc/sysctl.conf # Controls IP packet forwarding net.ipv4.ip_forward = 1 # 0 修改为1 保存退出 #需重启系统 [root@nginx-master sbin]# sysctl -p net.ipv4.ip_forward = 1 #修改生效 net.ipv4.conf.default.rp_filter = 1 net.ipv4.conf.default.accept_source_route = 0 kernel.sysrq = 0 kernel.core_uses_pid = 1
iptables配置
iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-ports 3128 iptables -t nat -A POSTROUTING -s 192.168.0.0/16 -j SNAT --to-source 192.168.8.10
iptables 根据你的实际IP来配置的。
实验遇到的QA：
Q：配置时，把好多功能都配置完了，启动时各种报错。
A:实际配置当中的，一个功能一个功能实际并测试，这样比较好查找故障的。
Q:squid启动时，提示cache 与 log 目录拒绝访问
A:查看配置文件内的cache_effective_user squid 然后对目录进行用户与权限的配置
Q：配置完代理服务器后，当然想测试一下服务器的性能的。
A：请参考：http://www.oschina.net/question/12_6110 我使用的siege，其它没有测试
测试结果如下：
squid
Transactions: 2000 hits
Availability: 100.00 %
Elapsed time: 9.30 secs
Data transferred: 6.89 MB
Response time: 0.04 secs
Transaction rate: 215.05 trans/sec
Throughput: 0.74 MB/sec
Concurrency: 7.70
Successful transactions: 0
Failed transactions: 0
Longest transaction: 0.54
Shortest transaction: 0.00
没有SQUID
Lifting the server siege... done.
Transactions: 956 hits
Availability: 99.17 %
Elapsed time: 396.96 secs
Data transferred: 109.31 MB
Response time: 26.62 secs
Transaction rate: 2.41 trans/sec
Throughput: 0.28 MB/sec
Concurrency: 64.10
Successful transactions: 956
Failed transactions: 8
Longest transaction: 78.13
Shortest transaction: 2.62
有写的错误的地方，喜欢大家批评指正的。
努力写好每一篇文章，拒绝当转发党。严格测试每篇文章。