title: Route setup for same destination through different gateway and different interface
body: <p>I have the following routes for eth5 in my Redhat.</p>
  
  <pre><code>$ route -n
  Kernel IP routing table
  Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
  10.0.8.0        10.185.2.14     255.255.255.0   UG    0      0        0 eth5
  10.0.10.0       10.185.2.14     255.255.255.0   UG    0      0        0 eth5
  </code></pre>
  
  <p>I need to add 3 routes to eth4.</p>
  
  <pre><code>10.0.8.0/24 via 10.185.130.14 dev eth4
  10.0.10.0/24 via 10.185.130.14 dev eth4
  10.0.12.0/24 via 10.185.130.14 dev eth4
  </code></pre>
  
  <p>The following command prompted the error message.</p>
  
  <pre><code>$ ip route add 10.0.8.0/24 via 10.185.130.14 dev eth4
  RTNETLINK answers: File exists
  </code></pre>
  
  <p>What is the correct approach to set up those routes? Thanks in advance.</p>