Linux 路由的添加删除-ip route

# route 
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         gateway         0.0.0.0         UG    0      0        0 eth0
link-local      0.0.0.0         255.255.0.0     U     1002   0        0 eth0
172.21.0.0      0.0.0.0         255.255.240.0   U     0      0        0 eth0


# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         172.21.0.1      0.0.0.0         UG    0      0        0 eth0
169.254.0.0     0.0.0.0         255.255.0.0     U     1002   0        0 eth0
172.21.0.0      0.0.0.0         255.255.240.0   U     0      0        0 eth0

# ip route show
default via 172.21.0.1 dev eth0 
169.254.0.0/16 dev eth0 scope link metric 1002 
172.21.0.0/20 dev eth0 proto kernel scope link src 172.21.0.15 

# ip route list
default via 172.21.0.1 dev eth0 
169.254.0.0/16 dev eth0 scope link metric 1002 
172.21.0.0/20 dev eth0 proto kernel scope link src 172.21.0.15

# netstat -nr
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
0.0.0.0         172.21.0.1      0.0.0.0         UG        0 0          0 eth0
169.254.0.0     0.0.0.0         255.255.0.0     U         0 0          0 eth0
172.21.0.0      0.0.0.0         255.255.240.0   U         0 0          0 eth0

# 1.添加默认路由信息，其中172.21.0.1是网关地址。
# ip route add default via 172.21.0.1  dev eth0
# 或者
# route add default gw 172.21.0.1

# 2.添加网络路由
# route add -net 172.21.0.0/24 netmask 255.255.255.0  dev eth0
#或者简写
# route add -net 172.21.0.0/24  dev eth0

#添加一条路由(发往172.21.0这个网段的全部要经过网关172.21.0.1)
route add -net 172.21.0.0/24 netmask 255.255.255.0 gw 172.21.0.1


# 3.添加主机的路由
# route add -host 172.21.0.64/32 dev eth0
# 或者具体地址
# route add -host 172.21.0.64 dev eth0

# 1.删除默认路由信息
# ip route del default via 172.21.0.1 dev eth0

# 2.删除网络路由
# route del -net 172.2.1.0/24netmask 255.255.255.0 dev eth0
# 或者简写
# route add -net 172.2.1.0/24  dev eth0

# 3.删除主机的路由
# route del  -host 172.2.0.64/32 dev eth0
# 或者
# route del -host 172.21.0.64 dev eth0

#删除完后，需要重启网络
# systemctl restart network

#查看路由信息
# route -n