ip address 10.20.0.0 19 ^ Error: Unrecognized command found at '^' position.

It seems like you are trying to enter a command related to configuring an interface in Cisco IOS, but the command syntax is incorrect.

The correct command syntax for configuring an IP address on a Cisco IOS interface is:

interface <interface_name>
ip address <ip_address> <subnet_mask>

For example, to configure an IP address of 10.20.0.1 with a subnet mask of 255.255.224.0 on interface GigabitEthernet0/1, you would enter the following commands:

enable
configure terminal
interface GigabitEthernet0/1
ip address 10.20.0.1 255.255.224.0

I hope that helps! Let me know if you have any more questions.