Scenario

Your server uses multiple network interfaces and may have incorrect routing for a specific subnet. You need to verify and fix it to ensure proper traffic flow.

Task

Display the current routing table to identify existing routes, check if a route for the 10.10.0.0/16 subnet exists and which interface and gateway it uses. If the route goes through eth0, delete the existing route and add a new route for 10.10.0.0/16 via gateway 192.168.100.1 using interface eth1.

Example

# Before (incorrect route through eth0)

10.10.0.0/16 routed via eth0
Gateway: 192.168.50.1
Traffic experiencing packet loss

# After (corrected route through eth1)

10.10.0.0/16 routed via eth1
Gateway: 192.168.100.1
Route verified and active

Step 1: Display the current routing table

route -n

This shows all routes with numeric IP addresses, avoiding slow DNS lookups.

Step 2: Check if the 10.10.0.0/16 route exists and identify its interface

route -n | grep "10.10.0.0"

Step 3: If the route exists and uses eth0, delete it

sudo route del -net 10.10.0.0 netmask 255.255.0.0

Step 4: Add the new route via gateway 192.168.100.1 on eth1

sudo route add -net 10.10.0.0 netmask 255.255.0.0 gw 192.168.100.1 dev eth1