Cisco || Configure Cisco (ISR C1121X-8P) Router

When I had to configure a Cisco (ISR C1121X-8P) router, I noticed it only had a Micro USB console port. I was able to connect using a standard cable, and this generated a COM8 port in Device Manager. I then successfully established a connection to that port using PuTTY at a speed of 9600.

enable

show running-config

configure terminal

 

hostname lifeisrouting.com

enable secret PASSWORD

 

ip domain-name lifeisrouting.local

crypto key generate rsa modulus 2048

username admin secret PASSWORD

ip ssh version 2

line vty 0 4

login local

transport input ssh

 
Configured the WAN port:

interface GigabitEthernet0/0/0

description WAN

ip address dhcp

ip nat outside

no shutdown

 
Configured DHCP and NAT:

ip dhcp excluded-address 192.168.100.1 192.168.100.10

ip dhcp pool LAN-POOL

network 192.168.100.0 255.255.255.0

default-router 192.168.100.1

dns-server 1.1.1.1 8.8.4.4

 

access-list 1 permit 192.168.100.0 0.0.0.255

ip nat inside source list 1 interface GigabitEthernet0/0/0 overload

The second interface was configured as a backup WAN. The switchport command is not applicable to this interface, meaning it cannot be logically combined with the other eight LAN ports. Therefore, it must be treated as a separate routed interface, which allows you to configure a distinct IP address (or a separate DHCP client) on it.

interface GigabitEthernet0/0/1

description WAN2

ip address dhcp

ip nat outside

no shutdown

 

Created interface vlan 1:

 

interface vlan 1

ip address 192.168.100.1 255.255.255.0

ip nat inside

Setting up eight LAN ports (default ports are in vlan 1, it is enough to specify mode access):

interface GigabitEthernet0/1/0

switchport mode access

switchport access vlan 1

no shutdown

 

 interface range GigabitEthernet0/1/0 - 0/1/7

switchport mode access

switchport access vlan 1

no shutdown

exit

Saving configuration:

write memory

copy running-config startup-config

Viewing various information:

show interfaces GigabitEthernet0/0/1 switchport

show ip interface brief

show ip route

show version

show ip interface brief

show running-config

Enabling an http server where you can view various statistics:

ip http server

ip http authentication local