General Information

Routing IP traffic and creating static routes.

The following virtual machines will be used:

• server1.example.com (192.168.1.150) → Configure the routes here

Finding help in this section.

• nmcli examples

  man nmcli-examples

Ensure IP Forwarding is enabled if using router like functionality

# Persistent Change that takes place upon system boot
vim /etc/sysctl.d/overrides.conf
 
net.ipv4.ip_forward = 1

Show Route Table

ip route show

Creating a persistent static route.

Interface specific route using nmcli.

• Create route

  nmcli con mod enp0s3 +ipv4.routes 216.58.219.0/24

• Bring up the new connection config

  nmcli con up enp0s3

• Verify route

  ip route show

• Open nmtui

  nmtui

• Enter on “Edit a connection”
• Select the target network interface to use, press Enter.
  • Scroll down to “Routing”, Enter on “<Edit…>”
  • Enter on “<Add…>”
    • Type the Destination/Prefix
    • Next Hop
    • Optional Metric (default static is 0)
  • Tab to <OK> and press 'Enter'
• Scroll to the bottom and Enter on “<OK>”
• Tab over to <QUIT>
• File is created at: /etc/sysconfig/network-scripts/route-<ifname>
• Restart the network service

  systemctl restart network

• View route

  ip route show

Note: This method is considered “legacy”, but if it works, that is all that matters on the exam.

• Create config file

  vim /etc/sysconfig/static-routes
   
  # Minimal route entry
  any net 216.58.217.0/24 gw 192.168.1.254
   
  # Can also specify a device to use for the route
  any net 216.58.217.0/24 gw 192.168.1.254 dev eth0
   
  # Can also specify a route metric
  any net 216.58.217.0/24 gw 192.168.1.254 dev eth0 metric 110

  • any → source from any
  • net 216.58.217.0/24 → traffic to this network destination
  • gw 192.168.1.254 → use this gateway
  • OPTIONAL: dev eth0 → use this device

• Restart the network service

  systemctl restart network

• View route

  ip route show