server：CentOS5.8
ip：172.16.8.11 Gateway：172.16.8.1
ip：10.120.6.78 Gateway：10.120.6.1
网卡配置：
eth0 point： [root@localhost ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0 # Intel Corporation 82576 Gigabit Network Connection DEVICE=eth0 BOOTPROTO=none HWADDR=80:FB:06:B0:F3:CE ONBOOT=yes IPADDR=172.16.8.11 NETMASK=255.255.255.0 GATEWAY=172.16.8.1 TYPE=Ethernet ech1 point： [root@localhost ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth1 DEVICE=eth1 BOOTPROTO=none HWADDR=80:FB:06:B0:F3:CF ONBOOT=yes HOTPLUG=no IPADDR=10.120.6.78 NETMASK=255.255.254.0
打开转发：
[root@localhost ~]# echo 1 > /proc/sys/net/ipv4/ip_forward 不知道这一步是不是有必要我临时打开了。
配置路由表：
[root@localhost ~]# cat /etc/iproute2/rt_tables # reserved values 255 local 254 main 253 default 252 net0 251 net1 0 unspec # # local # #1 inr.ruhep [root@localhost ~]#
使用ip route添加默认路由：
ip route add 127.0.0.0/8 dev lo table net1 ip route add default via 172.16.8.1 dev eth0 src 172.16.8.11 table net1 ip rule add from 172.16.8.11 table net1 ip route add 127.0.0.0/8 dev lo table net0 ip route add default via 10.120.6.1 dev eth1 src 10.120.6.78 table net0 ip rule add from 10.120.6.78 table net0 ip route flush table net1 ip route flush table net0
注意测试的时候指定源地址：
[root@localhost ~]# ping -I 172.16.8.11 www.baidu.com PING www.a.shifen.com (220.181.111.188) from 172.16.8.11 : 56(84) bytes of data. 64 bytes from 220.181.111.188: icmp_seq=1 ttl=52 time=8.69 ms 64 bytes from 220.181.111.188: icmp_seq=2 ttl=52 time=8.57 ms --- www.a.shifen.com ping statistics --- 2 packets transmitted, 2 received, 0% packet loss, time 999ms rtt min/avg/max/mdev = 8.575/8.636/8.698/0.111 ms [root@localhost ~]# ++++++++++++++++++++++++++++++++++++++++++++++++++ [root@localhost ~]# ping -I 10.120.6.78 10.11.240.22 PING 10.11.240.22 (10.11.240.22) from 10.120.6.78 : 56(84) bytes of data. 64 bytes from 10.11.240.22: icmp_seq=1 ttl=251 time=10.9 ms 64 bytes from 10.11.240.22: icmp_seq=2 ttl=251 time=10.6 ms 64 bytes from 10.11.240.22: icmp_seq=3 ttl=251 time=10.6 ms 64 bytes from 10.11.240.22: icmp_seq=4 ttl=251 time=10.7 ms 64 bytes from 10.11.240.22: icmp_seq=5 ttl=251 time=10.8 ms 64 bytes from 10.11.240.22: icmp_seq=6 ttl=251 time=10.5 ms 64 bytes from 10.11.240.22: icmp_seq=7 ttl=251 time=10.6 ms --- 10.11.240.22 ping statistics --- 7 packets transmitted, 7 received, 0% packet loss, time 6002ms rtt min/avg/max/mdev = 10.525/10.727/10.910/0.172 ms [root@localhost ~]#
PS：10.11.240.22 是我们的ipsec对端，是能够通过10.120.6.78 访问的。