#!/bin/sh # Set the name of the primary network interface primary_interface="eth0" # Set the name of the secondary network interface secondary_interface="wlan0" # Set the IP address range of the local network local_network="192.168.1.0/24" primary_interface_table="eth0_table" # Keep running the script indefinitely while true; do # Check if the primary interface is up and connected to the local network if ip addr show $primary_interface up | grep -q $local_network; then # Add a new routing table for the primary interface echo "200 $primary_interface_table" >> /etc/iproute2/rt_tables # Add default route for primary interface to the new routing table primary_gateway=$(ip route show | grep "default" | grep "$primary_interface" | awk '{print $3}') ip route add default via $primary_gateway dev $primary_interface table $primary_interface_table # Add a rule to route all traffic from primary interface through the new routing table primary_ip=$(ip addr show $primary_interface | grep "inet\b" | awk '{print $2}' | cut -d/ -f1) ip rule add from $primary_ip table $primary_interface_table # Remove any existing default route for the secondary interface ip route del default dev $secondary_interface else # Remove any existing routing table for the primary interface existing_table=$(grep -n " $primary_interface_table" /etc/iproute2/rt_tables | cut -f1 -d:) if [ ! -z "$existing_table" ]; then sed -i "${existing_table}d" /etc/iproute2/rt_tables ip route flush table $primary_interface_table ip rule del table $primary_interface_table fi # Add default route for the secondary interface secondary_gateway=$(ip route show | grep "default" | grep "$secondary_interface" | awk '{print $3}') ip route add default via $secondary_gateway dev $secondary_interface fi # Wait for 1 second before checking the network interfaces again sleep 1 done 运行上述脚本，提示ip: RTNETLINK answers: File exists

这个脚本的作用是检测主要网络接口是否连接到本地网络，如果连接上了，则将所有流量通过该接口发送，如果没有连接，则将所有流量通过备用接口发送。

关于你的问题，ip: RTNETLINK answers: File exists，是因为执行了添加路由的命令，但是该路由已经存在了。你可以先删除该路由，再执行添加路由的命令，或者使用`ip route replace`命令来替换原有的路由。

相关问题

#!/bin/sh # Set the name of the primary network interface primary_interface="eth0" # Set the name of the secondary network interface secondary_interface="wlan0" # Set the IP address range of the local network local_network="192.168.1.0/24" primary_interface_table="eth0_table" # Keep running the script indefinitely while true; do # Check if the primary interface is up and connected to the local network if ip addr show $primary_interface up | grep -q $local_network; then # Add a new routing table for the primary interface echo "200 $primary_interface_table" >> /etc/iproute2/rt_tables # Add default route for primary interface to the new routing table primary_gateway=$(ip route show | grep "default" | grep "$primary_interface" | awk '{print $3}') ip route add default via $primary_gateway dev $primary_interface table $primary_interface_table # Add a rule to route all traffic from primary interface through the new routing table primary_ip=$(ip addr show $primary_interface | grep "inet\b" | awk '{print $2}' | cut -d/ -f1) ip rule add from $primary_ip table $primary_interface_table # Remove any existing default route for the secondary interface ip route del default dev $secondary_interface else # Remove any existing routing table for the primary interface existing_table=$(grep -n " $primary_interface_table" /etc/iproute2/rt_tables | cut -f1 -d:) if [ ! -z "$existing_table" ]; then sed -i "${existing_table}d" /etc/iproute2/rt_tables ip route flush table $primary_interface_table ip rule del table $primary_interface_table fi # Add default route for the secondary interface secondary_gateway=$(ip route show | grep "default" | grep "$secondary_interface" | awk '{print $3}') ip route add default via $secondary_gateway dev $secondary_interface fi # Wait for 1 second before checking the network interfaces again sleep 1 done 运行上述脚本，提示ip: RTNETLINK answers: File exists， 请问如何修正

这个错误通常是因为重复执行了相同的命令，导致 ip 路由表中已经存在相同的路由规则。你可以尝试先手动删除相应的路由规则和路由表，然后再重新执行脚本。具体操作如下：

1. 删除路由规则和路由表：

ip rule del from $primary_ip table $primary_interface_table
ip route flush table $primary_interface_table
sed -i "/^200 $primary_interface_table$/d" /etc/iproute2/rt_tables

2. 重新执行脚本。

如果还是出现相同的错误，你可以尝试重启网络服务，然后再执行脚本：

systemctl restart networking.service

#!/bin/bash # Set the name of the primary network interface primary_interface="eth0" # Set the name of the secondary network interface secondary_interface="wlan0" # Set the IP address range of the local network local_network="192.168.1.0/24" # Keep running the script indefinitely while true; do # Check if the primary interface is up and connected to the local network if ip addr show $primary_interface up | grep -q $local_network; then # Add a new routing table for the primary interface echo "200 $primary_interface_table" >> /etc/iproute2/rt_tables # Add default route for primary interface to the new routing table primary_gateway=$(ip route show | grep "default" | grep "$primary_interface" | awk '{print $3}') ip route add default via $primary_gateway dev $primary_interface table $primary_interface_table # Add a rule to route all traffic from primary interface through the new routing table primary_ip=$(ip addr show $primary_interface | grep "inet\b" | awk '{print $2}' | cut -d/ -f1) ip rule add from $primary_ip table $primary_interface_table # Remove any existing default route for the secondary interface ip route del default dev $secondary_interface else # Remove any existing routing table for the primary interface existing_table=$(grep -n " $primary_interface_table" /etc/iproute2/rt_tables | cut -f1 -d:) if [ ! -z "$existing_table" ]; then sed -i "${existing_table}d" /etc/iproute2/rt_tables ip route flush table $primary_interface_table ip rule del table $primary_interface_table fi # Add default route for the secondary interface secondary_gateway=$(ip route show | grep "default" | grep "$secondary_interface" | awk '{print $3}') ip route add default via $secondary_gateway dev $secondary_interface fi # Wait for 1 second before checking the network interfaces again sleep 1 done 运行上述脚本，提示 ip: command line is not complete, try "help"

根据脚本的内容，出现 `ip: command line is not complete, try "help"` 错误的可能原因是 `$primary_interface_table` 变量未被定义。请确认你在脚本中是否定义了 `$primary_interface_table` 变量。如果没有定义，请在脚本中添加以下内容来定义变量：

# Set the name of the primary interface routing table
primary_interface_table="my_primary_table"

将 `my_primary_table` 替换为你想要使用的名称。