Linux production Proxy Server

Linux production proxy server-Linux Enterprise Application-Linux server application information. The following is a detailed description. The simplest way to use linux as a proxy server is to use RedHat9.0 as an example.

Take my computer as an example: because I only have one network card, I have edited eth0: 0. In reality, it is best to have two network cards.

Eth0 NIC address settings
[Root @ xiaoye root] # vi/etc/sysconfig/network-scripts/ifcfg-eth0 set according to your own situation can be edited by a save is: wq

DEVICE = eth0
BOOTPROTO = static
BROADCAST = 219.239.174.255
IPADDR = 219.239.174.15
NETMASK = 255.255.255.0
NETWORK = 219.239.174.0
ONBOOT = yes

Edit eth0: 0 as follows (Note: Based on the NIC's own situation
[Root @ xiaoye root] # cat/etc/sysconfig/network-scripts/ifcfg-eth0>/etc/sysconfig/network-scripts/ifcfg-eth0: 0
In this way, the content in eth0: 0 is the same as that in eth0. You only need to change the incorrect content.

DEVICE = eth0: 0
BOOTPROTO = static
BROADCAST = 192.168.0.255
IPADDR = 192.168.0.1
NETMASK = 255.255.255.0
NETWORK = 192.168.0.0
ONBOOT = yes

[Root @ xiaoye root] # ifconfig --- see whether two Nic IP addresses are displayed and whether they match your situation
Change the gateway address
　　　
HOSTNAME = xiaoye
GATEWAY = 219.239.174.16 by default, this one does not need to be added by yourself
In [root @ xiaoye root] # vi/etc/resolv. conf

Nameserver 202.106.0.20
Run the route command
[Root @ xiaoye root] # route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
219.239.174.0*255.255.255.0 U 0 0 eth0
169.168.0.0*255.255.0.0 U 0 0 0 eth0: 0
127.0.0.0*255.0.0.0 U 0 0 0 lo
Default 219.239.174.16 0.0.0.0 UG 0 0 0 eth0
Edit iptables forwarding rules
[Root @ xiaoye root] # vi/etc/sysctl. conf

It can be written as follows:
Net. ipv4.ip _ forward = 0 ------------ change 0 to 1 to enable the forwarding function (others do not move)
Net. ipv4.conf. default. rp_filter = 1
Kernel. sysrq = 0



[Root @ xiaoye root] # vi/etc/rc. d/rc. local --- this is automatically loaded after the system, which is equivalent to what I understand in WINDOWS :)
Iptables-F disable Firewall
Iptables-F-t create a rule for nat-t followed by a nat mangle filter)
Iptables-t nat-a postrouting-o eth0-s 192.168.0.0/24-j MASQUERADE
To create a nat rule POSTROUTING is to use this function to convert source IP addresses before forwarding packets. -O = output-s = source-j parameter is used to specify the action to be processed. MASQUERADE is rewritten to disguise the original IP address.
Echo 1>/proc/sys/net/ipv4/ip_forward enable ip forwarding.
Finally, reboot
You can try this method.