linux路由

网络拓扑

配置route主机

R1

网卡配置

eth0

TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=static
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
NAME=eth0
DEVICE=eth0
ONBOOT=yes
IPADDR=10.1.0.200
NETMASK=255.255.0.0

eth1

TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=static
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
NAME=eth1
DEVICE=eth1
ONBOOT=yes
IPADDR=10.2.0.200
NETMASK=255.255.0.0

查看路由表

[root@localhost network-scripts]# ip route
10.1.0.0/16 dev eth0 proto kernel scope link src 10.1.0.200 metric 100
10.2.0.0/16 dev eth1 proto kernel scope link src 10.2.0.200 metric 101

添加路由

临时添加

[root@localhost network-scripts]# ip route add 10.3.0.0/24 via 10.2.0.200 dev eth1
[root@localhost network-scripts]# ip route add 10.4.0.0/24 via 10.2.0.200 dev eth1
[root@localhost network-scripts]# ip route
10.1.0.0/16 dev eth0 proto kernel scope link src 10.1.0.200 metric 100
10.2.0.0/16 dev eth1 proto kernel scope link src 10.2.0.200 metric 101
10.3.0.0/24 via 10.2.0.200 dev eth1
10.4.0.0/24 via 10.2.0.200 dev eth1

添加路由后的路由表

[root@localhost network-scripts]# ip route
10.1.0.0/16 dev eth0 proto kernel scope link src 10.1.0.200 metric 100
10.2.0.0/16 dev eth1 proto kernel scope link src 10.2.0.200 metric 101
10.3.0.0/24 via 10.2.0.200 dev eth1
10.4.0.0/24 via 10.2.0.200 dev eth1

R2

TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=static
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
NAME=eth0
DEVICE=eth0
ONBOOT=yes
IPADDR=10.2.0.201
NETMASK=255.255.0.0

TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=static
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
NAME=eth1
DEVICE=eth1
ONBOOT=yes
IPADDR=10.3.0.200
NETMASK=255.255.0.0

添加路由

ip route add 10.1.0.0/24 via 10.2.0.201 dev eth0
ip route add 10.4.0.0/24 via 10.3.0.200 dev eth1

[root@localhost network-scripts]# ip route
10.1.0.0/24 via 10.2.0.201 dev eth0
10.2.0.0/16 dev eth0 proto kernel scope link src 10.2.0.201 metric 100
10.3.0.0/16 dev eth1 proto kernel scope link src 10.3.0.200 metric 101
10.4.0.0/24 via 10.3.0.200 dev eth1

R3

TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=static
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
NAME=eth0
DEVICE=eth0
ONBOOT=yes
IPADDR=10.3.0.201
NETMASK=255.255.0.0

TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=static
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
NAME=eth1
DEVICE=eth1
ONBOOT=yes
IPADDR=10.4.0.200
NETMASK=255.255.0.0

添加路由

ip route add 10.1.0.0/24 via 10.3.0.201
ip route add 10.2.0.0/24 via 10.3.0.201

[root@localhost network-scripts]# ip route
10.1.0.0/24 via 10.3.0.201 dev eth0
10.2.0.0/24 via 10.3.0.201 dev eth0
10.3.0.0/16 dev eth0 proto kernel scope link src 10.3.0.201 metric 100
10.4.0.0/16 dev eth1 proto kernel scope link src 10.4.0.200 metric 101

1.临时开启，（写入内存，在内存中开启）

echo "1" > /proc/sys/net/ipv4/ip_forward

2.永久开启，（写入内核）

在 vim /etc/sysctl.conf 下

加入此行   net.ipv4.ip_forward = 1

sysctl -p               ----加载一下

[root@localhost ~]# sysctl -a |grep "ip_forward"    ----查看一下
net.ipv4.ip_forward = 1

net.ipv4.ip_forward_use_pmtu = 0