Lab Objective:
Learn how to use the route command to display network information on Linux.
Lab Purpose:
Route is used when you want to work with the IP/kernel routing table. It is typically used to setup static routes to specific networks of hosts via an interface. It is used for updating or showing the IP/kernel routing table.
Lab Tool:
Kali Linux
Lab Topology:
You can use Kali Linux in a VM for this lab.
Some route command features may require high privileges to work. First of all, we have to be the “root” user using the terminal:
sudo su –
Lab Walkthrough:
Task 1:
In order to use route, you may need to install it. It comes in a package called net tools, and it can be installed on Kali Linux with the following command:
Sudo apt-get install net-tools
Once this is installed, we will first view the help screen using the following command:
route -h
We will then use a simple command to view our IP/kernel routing table:
route
Task 2:
If we want to display the previous routing table in ful numeric form, we can use this command:
route -n
This is useful for more accurately determining values in the routing table.
Task 3:
We can add a default gateway by executing the following command:
route add default gw xxx.xxx.xxx.xxx
Replace the x’s with the your gateway IP. This assigns a gateway address through which all packets that do not belong to the network are forwarded.
Task 4:
To view the kernel’s routing cache information, we can use the following command:
route -Cn
The cache is used to route the packets faster. This command will print all saved cache information.
Task 5:
We can specify to reject routing to a specific host or network using this command:
route add -host 192.168.1.51 reject
If we attempt to ping the above IP address, we will be presented with a “Network is unreachable” notice.
Task 6:
If we want to get the details of the kernel/IP routing table, we can use the following ip command:
ip route
This will detail the kernel/IP routing table.
Task 7:
In some instances, we may wish to delete the default gateway, which we can achieve by running this command:
route del default
NOTE: this may lead to some malfunctioning of your internet connection and it is important you take note of your default gateway before executing this command.
Task 8:
To get the output in relation to IPv4 and IPv6, we can use the following commands respectively:
ip -4 route
The above will display the entries with IPv4 only
ip -6 route
The above will display the entries with IPv6 only
