准备工作：
1.核心交换机H3C S5500 vlan划分10,20,30,40,50,60,70 七个vlan
2.安装CentOS 5.6服务器配置ip地址为外网eth0地址为192.168.200.9 子网掩码为255.255.255.0 网关为192.168.200.96 dns为202.101.172.46，eth1内网地址无。
3.外网为eth0，内网为eth1,物理连接eth1连接交换机的 trunk口。
1.首先配置H3C S5500核心交换机划分7个VLAN，利用SecureCRT连接交换机器如图所示：
<H3C>dis cu //进入交换机首先查看默认配置如下：
#
version 5.20, Release 2202P19
#
sysname H3C
#
domain default enable system
#
telnet server enable
#
undo ip ttl-expires
#
vlan 1
#
radius scheme system
server-type extended
primary authentication 127.0.0.1 1645
primary accounting 127.0.0.1 1646
user-name-format without-domain
#
domain system
access-limit disable
state active
idle-cut disable
self-service-url disable
#
user-group system
#
interface NULL0
#
interface GigabitEthernet1/0/1
#
interface GigabitEthernet1/0/2
#
interface GigabitEthernet1/0/3
#
interface GigabitEthernet1/0/4
#
interface GigabitEthernet1/0/5
#
interface GigabitEthernet1/0/6
#
interface GigabitEthernet1/0/7
#
interface GigabitEthernet1/0/8
#
interface GigabitEthernet1/0/9
#
interface GigabitEthernet1/0/10
#
interface GigabitEthernet1/0/11
#
interface GigabitEthernet1/0/12
#
interface GigabitEthernet1/0/13
#
interface GigabitEthernet1/0/14
#
interface GigabitEthernet1/0/15
#
interface GigabitEthernet1/0/16
#
interface GigabitEthernet1/0/17
#
interface GigabitEthernet1/0/18
#
interface GigabitEthernet1/0/19
#
interface GigabitEthernet1/0/20
#
interface GigabitEthernet1/0/21
#
interface GigabitEthernet1/0/22
#
interface GigabitEthernet1/0/23
#
interface GigabitEthernet1/0/24
#
interface GigabitEthernet1/0/25
shutdown
#
interface GigabitEthernet1/0/26
shutdown
#
interface GigabitEthernet1/0/27
shutdown
#
interface GigabitEthernet1/0/28
shutdown
#
user-interface aux 0
user-interface vty 0 4
#
return
<H3C>system-view //进入视图模式创建vlan 10,20,30,40,50,60,70 每个vlan成员端口为2个。
System View: return to User View with Ctrl+Z.
[H3C]vlan 10//创建vlan10和直接进入vlan10视图模式
[H3C-vlan10]port GigabitEthernet 1/0/1 to GigabitEthernet 1/0/2 //把1-2端口加入vlan10
[H3C-vlan10]vlan 20
[H3C-vlan20]port GigabitEthernet 1/0/3 to GigabitEthernet 1/0/4
[H3C-vlan20]vlan 30
[H3C-vlan30]port GigabitEthernet 1/0/5 to GigabitEthernet 1/0/6
[H3C-vlan30]vlan 40
[H3C-vlan40]port GigabitEthernet 1/0/7 to GigabitEthernet 1/0/8
[H3C-vlan40]vlan 50
[H3C-vlan50]port GigabitEthernet 1/0/9 to GigabitEthernet 1/0/10
[H3C-vlan50]vlan 60
[H3C-vlan60]port GigabitEthernet 1/0/11 to GigabitEthernet 1/0/12
[H3C-vlan60]VLAN 70
[H3C-vlan70]port GigabitEthernet 1/0/13 to GigabitEthernet 1/0/14
[H3C]interface GigabitEthernet 1/0/15 //进入1/0/15以太网端口视图
[H3C-GigabitEthernet1/0/15]port link-type trunk //设置15端口为trunk模式
[H3C-GigabitEthernet1/0/15]port trunk permit vlan all //设置15端口所有vlan都能通过
Please wait........................................... Done.
2.配置vlan的ip地址
[H3C]system-view//进入视图模式
[H3C]interface vlan 1//进入vlan 1接口模式
[H3C-Vlan-interface1]ip address 192.168.10.10 255.255.0.0//设置ip地址和子网掩码
[H3C-Vlan-interface1]quit
[H3C]ip route-static 0.0.0.0 0.0.0.0 192.168.20.254
3.配置web用户
[H3C] local-user admin //添加用户admin
[H3C-luser-admin] service-type telnet //服务类型为telnet
[H3C-luser-admin] password simple admin //设置密码为admin
[H3C-luser-admin] authorization-attribute level 3 //设置认证级别为3,0到3数字越小级别越低
4.telnet配置
<H3C> system-view//进入视图模式
[H3C-ui-vty0-4] user-interface vty 0 4 //进入虚拟终端 0 4
[H3C-ui-vty0-4] authentication-mode password //设置认证方式为密码验证方式为password
[H3C-ui-vty0-4] set authentication password simple 123456 设置登陆验证的password为明文密码”123456”也可以用cipher加密模式
[H3C-ui-vty0-4] user privilege level 3 配置登陆用户的级别为最高级别3(缺省为级别1)
[H3C] save //最后别忘记save
The current configuration will be written to the device. Are you sure? [Y/N]:y
Please input the file name(*.cfg)[flash:/startup.cfg]
(To leave the existing filename unchanged, press the enter key):
Validating file. Please wait...........
Configuration is saved to device successfully.
CentOS5.6服务器配置
1.[root@localhost zhh]# rpm -q vconfig //查看vconfig软件包是否存在不存在用yum -y install vconfig来安装即可。
vconfig-1.9-3
2.[root@localhost zhh]# yum -y install dhcp//安装dhcp服务
[root@localhost zhh]# chkconfig dhcpd off //关闭启动服务首先要先启动脚本vlan.sh，如果反过来dhpcd启动就会失败。
3.[root@localhost zhh]# cat vlan.sh //查看vlan.sh的脚本也就是添加vlan 10,20.30.40.50.60.70段vid一定要和你交换机创建的vlan名字一样
#!/bin/sh
vconfig add eth1 10
vconfig add eth1 20
vconfig add eth1 30
vconfig add eth1 40
vconfig add eth1 50
vconfig add eth1 60
vconfig add eth1 70
ifconfig eth1.10 192.168.10.254 netmask 255.255.255.0
ifconfig eth1.20 192.168.20.254 netmask 255.255.255.0
ifconfig eth1.30 192.168.30.254 netmask 255.255.255.0
ifconfig eth1.40 192.168.40.254 netmask 255.255.255.0
ifconfig eth1.50 192.168.50.254 netmask 255.255.255.0
ifconfig eth1.60 192.168.60.254 netmask 255.255.255.0
ifconfig eth1.70 192.168.70.254 netmask 255.255.255.0
/etc/rc.d/init.d/dhcpd stop
/etc/rc.d/init.d/dhcpd start
sh /root/zhh/iptables
4.[root@localhost zhh]# cat /etc/dhcpd.conf //dhcpd.conf配置文件如下：
# DHCP Server Configuration file.
# see /usr/share/doc/dhcp*/dhcpd.conf.sample
#
ddns-update-style interim;
ignore client-updates;
#//192.168.10.* //设置10段网络的ip地址池
subnet 192.168.10.0 netmask 255.255.255.0 { //subnet一个子网中的客户端，动态地指定ip地址，则在此subnet声明中，必须包含一组ip地址范围。
option routers 192.168.10.254; //网关地址
option subnet-mask 255.255.255.0; //子网掩码
option broadcast-address 192.168.10.255; //广播地址
option domain-name-servers 202.101.172.35;//dns ip地址
range dynamic-bootp 192.168.10.100 192.168.10.200; //地址池pool范围地址
default-lease-time 21600; //默认的ip租用时间期限单位为秒
max-lease-time 43200; //ip租用最长的期限单位为秒
}
#//
#//192.168.20.*
subnet 192.168.20.0 netmask 255.255.255.0 {
option routers 192.168.20.254;
option subnet-mask 255.255.255.0;
option broadcast-address 192.168.20.255;
option domain-name-servers 202.101.172.35;
range dynamic-bootp 192.168.20.100 192.168.20.210;
default-lease-time 21600;
max-lease-time 43200;
}
#//
#//192.168.30.*
subnet 192.168.30.0 netmask 255.255.255.0 {
option routers 192.168.30.254;
option subnet-mask 255.255.255.0;
option broadcast-address 192.168.30.255;
option domain-name-servers 202.101.172.35;
range dynamic-bootp 192.168.30.100 192.168.30.250;
default-lease-time 21600;
max-lease-time 43200;
}
#//
#//192.168.40.*
subnet 192.168.40.0 netmask 255.255.255.0 {
option routers 192.168.40.254;
option subnet-mask 255.255.255.0;
option broadcast-address 192.168.40.255;
option domain-name-servers 202.101.172.35;
range dynamic-bootp 192.168.40.100 192.168.40.180;
default-lease-time 21600;
max-lease-time 43200;
}
#//
#//192.168.50.*
subnet 192.168.50.0 netmask 255.255.255.0 {
option routers 192.168.50.254;
option subnet-mask 255.255.255.0;
option broadcast-address 192.168.50.255;
option domain-name-servers 202.101.172.35;
range dynamic-bootp 192.168.50.100 192.168.50.180;
default-lease-time 21600;
max-lease-time 43200;
}
#//
#//192.168.60.*
subnet 192.168.60.0 netmask 255.255.255.0 {
option routers 192.168.60.254;
option subnet-mask 255.255.255.0;
option broadcast-address 192.168.60.255;
option domain-name-servers 202.101.172.35;
range dynamic-bootp 192.168.60.100 192.168.60.140;
default-lease-time 21600;
max-lease-time 43200;
}
#//
#//192.168.70.*
subnet 192.168.70.0 netmask 255.255.255.0 {
option routers 192.168.70.254;
option subnet-mask 255.255.255.0;
option broadcast-address 192.168.70.255;
option domain-name-servers 202.101.172.35;
range dynamic-bootp 192.168.70.100 192.168.70.150;
default-lease-time 21600;
max-lease-time 43200;
}
#//
5.配置iptables NAT脚本如下：
[root@localhost zhh]# cat iptables
#!/bin/sh
MODPROBE=/sbin/modprobe //加载模块
IPTABLES=/sbin/iptables
#modprobe
$MODPROBE ip_tables > /dev/null 2>&1
$MODPROBE iptable_nat > /dev/null 2>&1
$MODPROBE ip_nat_ftp > /dev/null 2>&1
$MODPROBE ip_nat_irc > /dev/null 2>&1
$MODPROBE ip_conntrack > /dev/null 2>&1
$MODPROBE ip_conntrack_ftp > /dev/null 2>&1
$MODPROBE ip_conntrack_irc > /dev/null 2>&1
#clear old rules//清理原规则
$IPTABLES -F
$IPTABLES -X
$IPTABLES -Z
$IPTABLES -F -t nat
$IPTABLES -X -t nat
$IPTABLES -Z -t nat
$IPTABLES -P INPUT DROP
$IPTABLES -P OUTPUT ACCEPT
$IPTABLES -P FORWARD DROP
$IPTABLES -t nat -P PREROUTING ACCEPT
$IPTABLES -t nat -P POSTROUTING ACCEPT
$IPTABLES -t nat -P OUTPUT ACCEPT
iptables -I INPUT -p gre -j ACCEPT
# Open ip_forwad//打开转发功能
echo "1" > /proc/sys/net/ipv4/ip_forward
$IPTABLES -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPTABLES -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT
#$IPTABLES -A FORWARD -p udp -j ACCEPT
# Lan//局域网
for LAN in 192.168.0.0/16
do
$IPTABLES -A INPUT -p udp -s $LAN -m multiport --destination-ports 22 -j ACCEPT
$IPTABLES -A FORWARD -p udp -s $LAN -m multiport --destination-ports 5000,1701,1723,8001,7001,53,1755,8005,801,873 -j ACCEPT
$IPTABLES -A FORWARD -p udp -s $LAN -m multiport --destination-ports 5060,5063,10000,10001,12000,12001,20000,20001,22000,22001 -j ACCEPT
$IPTABLES -A FORWARD -p udp -s $LAN -m multiport --destination-ports 30000,30001,32000,32001,3388,7708 -j ACCEPT
$IPTABLES -A FORWARD -p icmp -s $LAN -j ACCEPT
$IPTABLES -A FORWARD -p tcp -s $LAN -m multiport --destination-ports 110,80,123,1701,2095,8001,3389,8181,2121,8005,801,1723 -j ACCEPT
$IPTABLES -A FORWARD -p tcp -s $LAN -m multiport --destination-ports 21,22,25,81,82,8080,443,1433,3214,1503,3128,3388,5632,5631 -j ACCEPT
$IPTABLES -A FORWARD -p tcp -s $LAN -m multiport --destination-ports 5050,7708 -j ACCEPT
$IPTABLES -t nat -A POSTROUTING -s $LAN -o eth0 -j SNAT --to 192.168.200.9 //启动NAT功能，192.168.200.9为进线地址如果电信给的静态ip就写电信给的静态ip即可.
done
6.[root@localhost zhh]# echo "sh /root/zhh/vlan.sh">>/etc/rc.local //把vlan.sh脚本放进/etc/rc.local让系统开机启动执行。
[root@localhost zhh]# cat /etc/rc.local
#!/bin/sh
#
# This script will be executed *after* all the other init scripts.
# You can put your own initialization stuff in here if you don't
# want to do the full Sys V style init stuff.
touch /var/lock/subsys/local
sh /root/zhh/vlan.sh
7.管理NAT服务器
[root@localhost ~]# iptables -L -n //查看iptables input,output,forward策略
Chain INPUT (policy DROP)
target prot opt source destination
ACCEPT 47 -- 0.0.0.0/0 0.0.0.0/0
ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED
ACCEPT all -- 0.0.0.0/0 0.0.0.0/0
ACCEPT udp -- 192.168.30.60 0.0.0.0/0
ACCEPT udp -- 192.168.10.10 0.0.0.0/0
ACCEPT all -- 192.168.0.0/16 0.0.0.0/0
ACCEPT udp -- 192.168.0.0/16 0.0.0.0/0
ACCEPT icmp -- 0.0.0.0/0 0.0.0.0/0
ACCEPT udp -- 192.168.0.0/16 0.0.0.0/0 multiport dports 22
Chain FORWARD (policy DROP)
target prot opt source destination
ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED
ACCEPT udp -- 192.168.30.60 0.0.0.0/0
ACCEPT udp -- 192.168.10.10 0.0.0.0/0
ACCEPT all -- 192.168.0.0/16 0.0.0.0/0
ACCEPT udp -- 192.168.0.0/16 0.0.0.0/0 multiport dports 5000,1701,1723,8001,7001,53,1755,8005,801,873
ACCEPT udp -- 192.168.0.0/16 0.0.0.0/0 multiport dports 5060,5063,10000,10001,12000,12001,20000,20001,22000,22001
ACCEPT udp -- 192.168.0.0/16 0.0.0.0/0 multiport dports 30000,30001,32000,32001,3388,7708
ACCEPT icmp -- 192.168.0.0/16 0.0.0.0/0
ACCEPT tcp -- 192.168.0.0/16 0.0.0.0/0 multiport dports 110,80,123,1701,2095,8001,3389,8181,2121,8005,801,1723
ACCEPT tcp -- 192.168.0.0/16 0.0.0.0/0 multiport dports 21,22,25,81,82,8080,443,1433,3214,1503,3128,3388,5632,5631
ACCEPT tcp -- 192.168.0.0/16 0.0.0.0/0 multiport dports 5050,7708
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
[root@localhost ~]# iptables -L -t nat //查看nat表POSTROUTING，以下已经说明客户端可以上网了。
Chain PREROUTING (policy ACCEPT)
target prot opt source destination
Chain POSTROUTING (policy ACCEPT)
target prot opt source destination
SNAT all -- 192.168.0.0/16 anywhere to:192.168.200.9
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
[root@localhost ~]# yum -y install iptraf //安装iptraf流量监控软件然后执行iptraf如下所示菜单
IP traffic monitor
General interface statistics
Detailed interface statistics
Statistical breakdowns
LAN station monitor
Filters...
Configure...
Exit
LVS（Linux Virtual Server）的NAT模型：http://www.linuxdiyf.com/linux/10757.html
SUSE Linux配置nat：http://www.linuxdiyf.com/linux/6167.html
Linux做NAT服务和端口映射的命令：http://www.linuxdiyf.com/linux/3606.html
NAT（ 网络地址转换）的实现：http://www.linuxdiyf.com/linux/2378.html
Linux的NAT实现浅谈：http://www.linuxdiyf.com/linux/3399.html