传说 负载均衡
1.添加网卡 插入网卡，启动机器，修改/etc/modules.conf并加入 alias eth2 driver.o 2.配置adsl拨号 通过adsl-setup程序创建ppp0和ppp1的拨号配置文件，并保存配置。 修改/etc/sysconfig/network-script/ifcfg-ppp*文件，将其中的PIDFILE参数设为： PIDFILE=/var/run/ppp-adsl*.pid 其中*对应0、1等 如果不修改此参数将无法启动第二个ppp接口。 3.启动ppp接口 因为adsl-start 命令缺省只能启动第一的ppp接口。所以要启动两个接口，必须指定配置文件。 adsl-start /etc/sysconfig/network-script/ifcfg-ppp0 adsl-start /etc/sysconfig/network-script/ifcfg-ppp1 4.添加路由表 缺省情况下，系统只有3个路由表，local、main、default，路由规则为所有进入的数据报都参照main、defaul来决策路由，这可以通过ip rule ls来查看。其输出如下： 代码: [root@linuxrouter root]# ip rule ls 0: from all lookup local 32766: from all lookup main 32767: from all lookup 253 [root@linuxrouter root]# 要实现策略路由，添加额外的路由表是必须的。 下面两条命令分别添加名为ppp0和ppp1的路由表。 echo 201 ppp0 >> /etc/iproutes/rt_tables echo 202 ppp1 >> /etc/iproutes/rt_tables 5.创建路由表项 上面创建的两个路由表都是空表，需要在其中注入路由表项。 本人编写了如下脚本用于注入路由表项： 代码: #!/bin/bash # Name: cprt # This program copy the route from route table to route table, # exclude the default route entry. if [ -z "" -o -z "" ]; then echo $"usage: cprt " exit 1 fi SOURCE= DEST= # Clear the destination route table echo $"Clearing route table $DEST ......" echo /sbin/ip route flush table $DEST # Inject routes from source to destination echo $"Injecting route from $SOURCE to $DEST ......" /sbin/ip route ls table $SOURCE | grep -v default > /tmp/route-tmp while read line; do /sbin/ip route add table $DEST $line done < "/tmp/route-tmp" 把main表中的路由表项复制到ppp0和ppp1中。 将下面命令加入到/etc/rc.d/rc.local中。 cprt main ppp0 cprt main ppp1 此时，两个路由表中都有相同的路由表项了，除了default路由以外。缺省路由的添加要通过另外的途径添加。当ppp激活，或者掉线时，pppd守护进程会调用/etc/ppp/目录下的ip-up、ip-down脚本，这些教本又分别调用ip-up.local、ip-down.local。在此我们利用这两个脚本来对路由表和流量控制策略进行维护，此脚本需要人工创建。 下面时本例中的脚本： 代码: #!/bin/bash # Name: ip-up.local # Created by lyking@CU check_default_route () { LC_ALL=C ip route list table match 0/0 | grep -q default } # Determin device here # We should use IFNAME as the interface name.For some reason, the IFNAME maybe not # same as the LINKNAME. And the route table should associate with the IFNAME. For # some conveniency, I name the route table as "ppp0" and "ppp1". RT_TABLE=$IFNAME # Add or change static route here if [ ! `check_default_route $RT_TABLE` ] ; then ip route change default dev $IFNAME table $RT_TABLE else ip route add default dev $IFNAME table $RT_TABLE fi # Write some messages for later trubleshooting. echo >> /var/log/ifchang.log echo ": $IFNAME going up at `date`." >> /var/log/ifchang.log echo ": $IFNAME got address: $IPLOCAL, peer address is $IPREMOTE." >> /var/log/ifchang.log echo ": Table $RT_TABLE default route change to `ip route ls table $RT_TABLE | grep default`." >> /var/log/ifchang.log # Refresh routing cache to activating the routing immediately. ip route flush cache 代码: #!/bin/bash # Name: ip-down.local # Created by lyking@CU cd /etc/sysconfig/network-scripts . network-functions # Determin device here # We should use IFNAME as the interface name.For some reason, the IFNAME maybe not # same as the LINKNAME. And the route table should associate with the IFNAME. For # some conveniency, I name the route table as "ppp0" and "ppp1". RT_TABLE=$IFNAME PPPS="ppp0 ppp1" # Looking for a valide connection to Internet DEFAULT_RT="" for i in $PPPS ; do echo "Checking $i ..." >> /tmp/if-down.log if [ ! `is_available $i` ] ; then echo "$i is available." >> /tmp/if-down.log DEFAULT_RT=$i break fi done # Update default route here if [ $DEFAULT_RT != "" ] ; then ip route add default dev $DEFAULT_R